[Closed] memory map adventurer unit - rate it?

I'm thinking of getting a memory map adventurer, probably the bigger 3500 one - to anyone who's got/used one, how do you find it?

I'm more interested in the "on the bike" rather than the "at home" rating = i.e. I want to know how the unit itself actually performs out in the countryside, not how confusing you find its software and how frustrating it is to transfer maps onto it and what sites it does and doesn't work with etc.

Does it keep its gps signal within woods?
Are the 1:50k maps detailed enough to read/zoomed in enough to be able to read on the screen to know where you are?

Given that the maps are OS raster maps, rather than basic line-drawn maps, do they always face north, and you move down the screen if you're going south, or does it have a compass so 'up' is always north? If the latter, then does its compass work well enough even at slow speed?

Thanks very much