My first kit I purchased from a Vancouver based company about 5 years ago and it is still working well. I used it for commuting 32 kms round trip to work. The second I got for my wife and is still fairly new. The kits are very easy to install on generic mountain bikes. It took one evening and was essentially plug and play. No cutting crimping or soldering. I opted for the optional cycle analyst on one of the kits. The geared hub motor has a slight whine that is virtually undetectable except on start up. When I bicycle beside somebody they have no clue the bike is electric as the rear hub is fairly small and the battery is kind of hidden either in a side bag or in the double rear carrier.