I cae across this American site, Electric Star, which has some succinct 2012 appraisals of various bikes available in the UK> It also has some other good pithy advice. There is an interesting observation on the Home page:
Buyer beware: there is a lot of “garbage” in this marketplace, as well as a lot of poor information. This is a young and emerging technology which has undergone big growing pains. Many of the products in the past were not ready for prime time. And some of the big box stores carry cheap products of inferior quality that are, in a word, junk. The best of these may serve the purpose of introduction. Unfortunately, most of the cheap electric bikes do not perform properly, break down frequently, and have poor manufacturer’s support. There are also a lot of inflated claims for range, power, and speed, so it is difficult – if not impossible – to understand this industry by surfing the internet. Power ratings of bikes are suspect because it depends on the configuration and design of the motor. Plus, many manufacturer’s think that just because it is electric, it doesn’t need to have decent bicycle components or ride well as a standard bicycle. This is likely the reason why many conventional bicycle shops have a bias against electric bikes.