Check out last month's LOOP if you can, it had a big GPS test supplement which included FlyAngel. It didn't come out too well by all accounts, the inferrence being that it was rather compromised, as in it was neither an outstanding aviation GPS nor an outstanding road GPS. A pity really as I'd considered one myself. It does have the big advantage of displaying the standard half-mil maps though. I'm currently looking at the Lowrance600 (£300-ish) as I didn't fancy spending £650.
I've never used one and am just relaying info, so check it out for yourself in the flesh, you may think it's perfectly good and are happy with it, it's your money after all.
dB