In reply to Indy:
> Did do a UKC search but to my surprise got zero hits.
>
> Will be doing a London 2 Paris bike ride in September. This has spurred me into finally looking to get a mapping bike computer. Edge 810 seems to be it. If anyone has one are there any interesting details that I need to take into consideration? Like say poor battery life.
>
> Also might seem like an odd question but the 810 does know its attached to a bike doesn't it? So you don't get routed on to motorways etc
Don't have an 810, but do have an 800 which are very similar (other than the tracking and sharing stuff). routing wise there's loads of preferences so you can choose quieter roads, or off-road routing.
Battery life is good for 14 hours if the screen brightness is low enough (you can set it so it goes completely blank inbetween instructions if you need to extend the life more) however if the battery does go flat you will loose your current ride's data.
I went for a version with O/s 1:50k maps of UK, which is great as I now have a hand holdable gps device for the mountains too. However, if cost is an issue and you'll mainly be on-road, then consider getting the unit only, and then downloading the open street map maps - these aren't as good as os maps, but fine on-road (and okish offroad - they often have foorpaths marked as bridleways)
If you are getting one for this ride, then get it early as it takes a while to set it up as you want (there are litterally hundreds of different measures to choose from) and get used to how to load tracks so you get turn-by-turn nav etc.
It does work perfectly with Bikehike.co.uk which I think is a real plus for route planning, and uploads straight to strava too