I've used a Wee-Ride CoPilot for a few years with my daughter. She enjoyed it. The quality of any Kent Bike product is so-so, but for light duty use these are fine. I did have one with a hub srocket that went bad in the 1st 15 miles of use. I called support and was shocked to get through to a live human being in a matter of seconds. Even more shocking it that they sent me an entire new unit at no cost to me. I spent $20 and the LBS and got the "bad one" repaired. My sister used the repaired one for a few years. After about 3 years of use the units all look as good as new. I paid under $70. I bought an extra mount and attached it to our cheap Kent Tandem and we rode a few tires as a triple. That was lots of fun. Start is a bit tricky, but once under way things are stable. I bought both the tag along bike and the tandem from Kent because these would get light duty use. So far both a fine. I would NEVER try to commute or do any serisou riding on a Kent bike as they are heavy, crude, with low end components, but I have been content with both of these products. Going on rides with my daughter was fun and at least I didn't have to worry about her and traffic. I knew exactly where she would be... 3 feet behind me. Last year my daughter finally got good at riding solo and this year she is having a blast on her Trek MT220. Now she can keep up with me without any problems.
Happy riding,
André