Pros: size, voicecommand, powered-mount, up-ahead, volume, navigation functionality, traffic, junction view, lane assist, etc.
Cons: Bluetooth sound quality and functionality issues, Users Manual, Battery Life.
In general I like the 2797LMT as an upgrade, in my case, from the 1490T, except for poor Bluetooth/Phone sound volume and quality plus an outgoing call/connection problem I haven't solved yet.
Size: This is one really big boy sitting on my Subaru dash but it works surprisingly well with a beanbag mount...a 1490T on steroids. No major sight obstruction thru the windshield. Portability might be a problem for those who have several cars or rent often. The power mount is a plus; easy to connect/disconnect. Probably not a good idea to suction mount to the window since if it releases (and it will eventually) you will have a large electronic piece flopping onto your lap. At least with the beanbag, it can't flop too far. Later, I may super glue the suction disk to the beanbag to make sure. Note, the suction mount has a larger diameter suction disc than previous mounts because of the 2797 increased weight.
At approx 1 to 1.5 hours, it could be better. But I suspect the unit was not designed to be used w/o car power, especially since the Traffic feature would not work without the GTM antenna enabled via the power cable. Not clear about the optional AC charger specs since the supplied GTM antenna cable indicates 2amp delivered to the hot mount but the garmin charger appears to be a 1 amp charger? If so, than any 1 amp charger will work as long as you can connect to the 2797 direct with a micro USB tip. Note, the GTM cable to the mount connects with a mini USB tip. You can also connect to your PC with the supplied USB to Micro USB GTM cable, but I have to believe it would take longer to charge considering USB can only deliver 500 milliamps.
Display: Doesn't seem as `contrasty' or vividly color saturated as my 5" 1490T prob due to the same pixel count on the larger 7" format. I changed the Map Theme to `Germany' since it looked somewhat similar to my Nuvi 660's theme, with gray streets against a tan background. Seems a bit better. It was not clear whether their Map Theme Files software version 2.70 (as of 2/9/2012) was already included in my 2797's software out of the box this month. I don't like to load anything via a Garmin update unless I absolutely have to!
The 7" screen gives you a lot of situational awareness, local street geography. Can be a bit distracting on freeway travel but easy to zoom in to minimize. Nice to see where you are in relation to other hwys and major roads w/o need to use the `look down' view I used on the 1490T.
Note, the screen format is fixed at landscape; it cannot rotate to portrait.
Volume: Really loud at max. Easy to hear nav instructions over road noise. 'American Samantha' default voice needed for the 'real directions' is very clear and distinct.
Basic Navigation: No problem so far. Updates and finds locations very fast. Time to destination right on the money. It does not say 'recalculate' anymore and that appears to please many, but not me. I like a heads up warning. Useful if you are not concentrating on where you are going. I wish too Garmin had kept the old warning 'bong' that would precede instructions. Having either or both as an enabled option would be nice.
Traffic: Works real well here in NYC metro area. This version is much more detailed and far-seeing than my 1490T. I can see multiple incident detail many miles out, both as it occurs (via warning) during the route and a look-see in advance. The warning detail is amazing. I originally thought this had HD traffic but it is NOT the case. Even so, this solution works fine.
Up Ahead: Very useful feature made even more so by ability to customize. I set Hospital, Food, and Gas on mine. Would have been nice if this was enabled via the Voice Command.
Voice Command: Works better than I expected. I estimated 75% effective so far. Might do better later on as I figure out my speaking voice volume and patterns.
Address Search: Not as simple and quick as 1490T. Not sure why they designed the default to take longer to search for street/destination in 3 or 4 surrounding states. But once you get hang of it, its ok I guess, and you can always add the state to localize/quicken the search, for ex. If you are driving from NY to a MA location.
Shortcut: Nice feature where you can include your favorites (icons) for quick search to frequent destinations. Need to get used to the new terminology: Waypoint and Saved Places instead of the old 'favorites'.
Bluetooth (BT): Good and bad here. Pairs up real quick with some phones but not all. Garmin's recommended Galaxy S3 (for the 2797) wouldn't even handshake.
I noted a major problem with mediocre sound quality/volume and initial outgoing call connectivity. With my own non-smart Samsung Convoy 660 it didn't seem to connect automatically, especially when using Voice Command to initiate the call. After call is made, I found I needed to press the 'head set button' a couple of times on the displayed 'In call options' box to actually hear the ringing and recipient's voice. I really hope it is a firmware and not hardware problem.
I was especially looking forward to problem free use of Voice Command with the BT feature. Should have been an unbeatable combination. But not too happy so far.
I tested the 2797 also with the I4S, Galaxy S3, and Droid Razor phones to see if the problem is unique to my Samsung Convoy 660. The Razor functioned the best but still had a sound quality/volume problem.
Would have given it 5 stars except for the Bluetooth issues.
USAGE UPDATE 4.18.13:
Gotten used to the 'less contrasty' screen; not too bad after all. Went back to the 'Garmin' default map theme as it seems to look the best, for me.
Still a BT volume/sound quality/connection problem with my Samsung Convoy 660 on Verizon system. Tested several others, courtesy of my guy Frank at local Radio Shack. The Galaxy S3 wouldnt even 'handshake' and that was on garmin's recommended list. Droid Razor tested best but still with low volume and iffy sound. Perhaps you need to ensure your phone works the way you want before you buy,if BT is a major reason for purchase. Not so much for me so I will live with it and hope garmin comes out with a firmware fix.
In general works fine. When you override the instruction, seems the unit sometimes can't recalculate fast enough to alert you to the new direction in time, so you are already past the directed turn street. I found this on 30mph local streets where the alternate turns were very close to each other, but if you drive a bit slower in these known situations, unit will work ok.
I suspect the POI file of supposedly 6mil (or is it 8mil now?) locations is not sufficiently up to date, for example missing some restaurants and schools that have been at same local addresses for well over 15 years.
A bit confusing here too since apparently you need to load other/custom POI files to make Proximity Alert work with garmin's POI Loader Software, even though the Manual doesnt explain this. I got it to work with the POI factory red light camera file. Haven't found out yet where the School Proximity Alert POI file comes from. I get no warnings near 5 local schools but just got one going by a school 15 miles away. No help yet from garmin support.
** In general, very pleased with 2797 performance. I trust in time, most of my 'issues' will be settled with software updates.
Usage Update 4/25/13:
Finally got an explanation from Garmin of how the School Proximity Warning works. Schools category in where to accesses the POIs on the GPS. School zone warning is part of the mapping software along with the POIs. But since this is a new feature not all schools in the POIs have been encoded with the proximity alert from their map vendor, navteq. I note that many schools are also missing from their POI file. So it is a two fold issue. They hope to have updated much of this information in subsequent map and firmware updates.
Usage Update 5/12/13:
Finally, should mention I am overall pleased with the 2797 performance, except for Bluetooth. Sent letter to garmin president and was essentially blown off by one of their minions, saying they are looking into the problem etc. Especially note the sleep power mode and real directions as two very useful features. I find myself always using the unit regardless of destination, even local, because enjoy playing with all its features. Should note also the POI Factory's red light camera app is a useful addition via garmins POI Loader.