Another thought, which I hope members here can help me on:
Why choose an off-the-shelf model when you could (fairly) easily get your ordinary bike electrified? What are the advantages of a Wisper, a Kalkhoff, or whatever, over an ordinary bike with a motor and battery attached?
good question. i think we are going through the same selection process allen.
in terms of new bike versus conversion....
from my research so far, it seems to that if you want a serious bike for really extended, proper use that you can rely on then you have to spend at least £1600. If money isn't an option and you need a new bike anyway then it's probably a no brainer.
but if money is an issue and you already have a decent bike then the Alien kit conversions seem like a really good option. they do have one year warranty i see. but the by-product of installing the kit yourself seems to me that you are probably improving your own chances of being able to troubleshoot any minor problems that do occur, which seems advantageous.
if money isn't an issue and you have a decent bike already then converting seems to be a not too expensive shot at an electric bike which could ultimately be a great success! it's definitely appears a more risky thing to do than buying new but then again sometimes things just work out really well don't they? if money really isn't an option then you could try the conversion and if it doesn't go that well, then buy a new one afterwards. i reckon though it helps if you
want to get more into the mechanical maintenance of bikes.
a brand new e-bike is also going to attract more light fingered attention than an old bike with odd looking racks and bits and bobs on it. handy depending on where you go with your bike.
overall though, it seems that it's all about how much you're going to use it and whether it encourages you to get out on the road with it.
hmmm.........

decisions decisions