I have only used this device once so far and am pretty impressed with its capabilties.I am dissapointed that it has no grid reference ability for the u.k, as I bought it to locate ancient trees and these are done via the u.k grid system as apposed to n degree etc. I cant say too much as yet but will update this as and when I encounter issues, however, I do not think i will ever regret buying this over cheaper options either in the Garmin or other brand categories. As far as turn by turn support is concerned seems daft to be overly concerned with this like some people are, car sat nav is cheap these days and better off buying a product just for the car.
The reception is excellent in this device and works indoors and under heavy canopy which was my main reason as I spend much of my time in deep wooded terrain, but it is winter, lets see how it copes when the broadleaf forest is in full summer foliage!
having now had a good play with the device I can give some pros and cons to this device, I will start with the pros.
First thing Ive noticed is the ease in learning by trial and error how to use and fully realise ALL the functions within the device, I had no previous GPS knowledge but this was a piece of cake. if your new to this GPS world, buy this and you wont go wrong, a 5 year old could find thier way around the globe with this!
The reception is very good, and the detail of reception information usefull as for example GPS acuracy readouts, typical 29-40ft acuracy sometimes better sometimes worse.
I can state that there is no need to buy turn by turn road navigation maps, it does have a road nav lock and is more than adequate. Turns shown well in advance, and a bleep signaling ahead of a new turn a pink track indicating the route and overlayed ahead a white overlay indicating the turning path or roundabout/junction approach. You will find this much less anoying than that repetative voice of typical sat nav for vehicles! Road navagation SORTED
Another usefull aid for me being an angler is the area measuring facility, i can now walk around the lake and get a reading of the acerage of the lake i am targeting! and enter waypoints of my favourite swims! essential on BIG waters.
defo buy the topo maps on the micro sd cards if your on walkabout, these maps are awsome, though could be more detailed in 20ft ranges as aposed to the bigger picture, but thats asking way more than is fair.
overly hungry on batteries, be warned, get som nimh rechargeables! alkalines and lithiums will be swallowed whole like candy!
compatability with 3rd party maps nil, will cost garmin in the long run.
not a lot of negatives, i love my 400t its awsome and I will never be wothout a GPS device EVER again it has enhanced my view of my favourite places and my enjoyment and experiance of going to new places, awsome.