We have an Xtracycle, Trail-gator, and a trailer. I have the Xtra/trailer, my wife has the TG. For me, the trailer isnt much weight up/down hill but with head winds you really feel it. The added weight of the Xtra is only noticed when I have to pick it up. I also have an attachment for the older kids' bikes. I cant take the front tire off and attach thier bikes to my Xtra while they ride stoker on the deck. The first few times doing this took some gettin used to, but it wasnt long before we got the hang of it..

My wife occasionally pulls our 8 year old with the TG and she said it was difficult at first, but once her and the boy got it figured out it was easy peasy. As for the leaning issue, he can only lean so far before he falls off and minor back/forth doesnt seem to bother her.

So I guess in short, any setup will take some practice, but shouldnt be long before you and the kids are enjoying our rides together =)