1. Big internet upload/download speed improvement over my old 3Com combo modem/router/switch
2. Improved reliability over my old 3Com - fewer timeouts and dropped VPN connections
3. Big speed improvement in wireless performance between 802.11n and 802.11g
4. VPN passthrough support less tolerant than old 3Com (also a con, see below)
1. Requirement for an external ethernet modem (a nuisance and cost but not a big deal)
2. VPN passthrough support less tolerant than old 3Com - took several days of trouble-shooting which eventually required a Cisco VPN client upgrade - not the router's fault, but a pain
3. 5GHz 802.11n wireless range very limited (to be expected)
4. 2.4GHz 802.11n wireless range more limted than 802.11g (to be expected, but more limited than I expected)
5. Harder to see DSL connection status, faults, diagnostics when using an external modem makes fault finding trickier
6. (getting very picky now) Can light up a room with its array of very bright LEDs
Excellent, dearer than basic products but works well. Not for the novice.
I bought this as a replacement for a 4 year old 3Com 802.11G DSL modem/router/hub. I wanted dual band wireless N (with both bands simultaneously active - look carefully, many other products don't do this, the giveaway is normally the price, if it's much less than £100 it probably isn't simultaneous), but also wanted gbit wired ports too.
Having shopped around a bit I settled on this as being the nearest to my requirements. To move closer to perfection it would have had to have had a built in DSL modem, but in all my searching I couldn't find a simultaneous dual-band wireless N device with gbit ports and a built in DSL modem, there is just about every other permutation of the various technologies, but as of now, no-one (I looked at Netgear, Linksys, D-Link, Vigor and a few other more obscure brands) seems to combine all three.
The above is an important point. For those who haven't read or don't understand the specs of this device, you cannot connect it directly to a BT (or other provider) ADSL (broadband) connection. You need a separate ethernet modem. Other reviewers have marked this router down because of this point, but it's perfectly clear from the spec and if you don't understand this or what you need to use to overcome this, then it's probably not the product for you. Because of the lack of a built in modem I've combined mine with a separate Ethernet Modem (I've used a Vigor V120, but I'm sure Netgear's own product would do the job just as well).
I had a big problem getting my company's VPN client to work through this and was about to return the router as a result. However, some extensive testing revealed the problem to be with the ancient version of the Cisco VPN client I was using, not with the router. A VPN client upgrade fixed my problem and it's been solid as a rock since. The dificulty here is that the router provides very little diagnostic and logging detail and combined with the need to use an external modem, makes diagnostics rather tricky. Don't let this put you off though.
The 802.11n range on both 5GHz and 2.4GHz signals is more limited than the range of my old 802.11g device, but this is to be expected. It is quite a bit more limited than I had expected though. My old 802.11g device could happily deliver a reliable (though poor) signal through two thick walls across a range of about 30M. The 5GHz signal barely makes it through a single wall and only about 30M with no obstruction at all. The 2.4GHz signal can penetrate the walls but won't reach as far as the old 802.11g device did. However, it is running at higher data rates, so I'm not surprised by this and the beauty of having simultaneous 2.4GHz & 5GHz signals is that it doesn't matter if the range of the 5GHz signal is short because you can still pick up the 2.4GHz.
If you're connecting this to a DSL broadband connection, this is not one for the novice. You'll need to know what you've bought, what else you need to make it work and how to configure it. It's not complicated, but does require a small amount of knowledge or (heaven forbid) reading the manual.
Overall I'm really pleased. My Internet speeds and reliability have improved and the wireless performance is far better. Getting to the bottom of my VPN issues was a pain, but this isn't really the router's fault, it just didn't give me a lot of information to help in diagnosing the problem. Would definitely recommend.