My son got a balance bike (Strider, which I find to be very well made and nice looking and I'm picky so I'm not sure where the thoughts of it being cheaply made come from) for his 2nd birthday. He LOVES it. At 31 months he's now easily coasting down hills and lifting his feet from the ground to glide on flat surfaces. On inclines he often stands and walks straddling the bike. It is VERY lightweight, enough that he can pick it up and carry it up and down the stairs which means that "falls" are a non-issue, he just stands right back up. The light weight also makes it easy on me, I can hang it off of the stroller when he doesn't want to ride it anymore and it doesn't add any weight to the stroller or tip it back.
When they first get the bikes, they usually walk beside them for awhile, then straddle the bar and walk over them for awhile, then start trying to sit on the bar or straddle the seat, then finally sit on the seat and walk. Coasting seems to come a few months after walking/running on the bike.