Hi...I bought an Urban Mover UM44S U Sprite back in September 2010...this is a supposedly more powerful model with a 36v battery, than the one Halfords stocks and alleges in the brochure a 50 mile range, ....although I struggled to get 30 which was the more realistic figure Mark quoted me pre purchase.
I paid a £1000 for it and been highly delighted, I've put 2500 miles on it since purchase with never a minutes bother but I always felt that given any trouble I could rely on Marks expertise to put it right.
Whether or not that'd be the case now remains to be tested.
I believe someone has already suggested buying just one for starters, which is a good idea.
Because of an accident I'm looking for stepthrough model and if I could lay my hands on a UM 44SL U Sprite which is the ladies model of my bike at the right price, I'd be very tempted.
Not sure how much you could rely on Halfords for after sales but I found my UM to be very reliable.