Here is a picture (I think) of our Craigslist Trek T900. Upgraded with Crank Bros Candy pedals, WTB Speed V seats, Avid Speed Dial 7 brakes, SRAM Rapid Fire shifters and Titec bars, stem and grips. My 8 year old and I took it out for our first ride together around the neighborhood. We plan to use it for rail trails and light mountain biking.
It does have a unique feel but I noticed its very comfortable and smooth. I though I would be pulling my son around but was shocked how much I power he provided when he was pedaling hard. Its going to take a little time until he gets used to clipping in so we will stick to pavement for now.