Nice piece of hardware if a touch bulky.
I got the OS 1:50 full GB map bundled with mine but the quality of the map is quite poor, it is like a low rez PDF picture of the paper map and the off road trails in red are not that clear.
Also your track line, as with the Zumo, is in turquoise, so the same colour as rivers and gridlines, and a bit confusing. Not sure if the colour can be changed?
The original writing on the OS map is still shown west/east so if you head south the writing is upsidedown. There is some extra Garmin wording for town names etc that superimposes on top.
I only got mine for the OS mapping but other than that, there is not a significant amount of features that the Zumo does not posses.
Good
OS Mapping
Good battery life
Option of using AA batteries once the rechargeable is dead ~ good for the trail
Camera ~ on the 650T option
The optional bike mount seems quite rugged and if fitted to an, again optional extra, RAM ball system you can handlebar mount with the camera facing forward to snap as you ride, even past a GSA screen. With the RAM you can use the Montana in either portrait or landscape so you can choose to either see what is coming up ahead or what is to the side.
Bad
All mounts are extra
Price~difficult to justify extra cost over that of the Zumo although it is a different animal for different uses.
No road routing unless you get the additional GB Discoverer maps
In road routing you cannot navigate with just the postcode, you need the address as well ~ old software technology.
I will add some more when I come across it with more usage.
I got mine from Tom at
www.lovingoutdoors.com and paid £599.00 including the OS map which normally sells for £200.00 and Family Pass to National Trust normally £30.00 (still await arrival of this though).
Very helpful internet company with real people on the phone who know their stuff. I have had it 3 weeks now and probably paid a "new bling" premium, it is probably on offer now but I dare not check.