What style(s) have you used?
What size did you use (and how big was your baby, approx)?
Small on 6 week old, medium on 14 month old, both big for their age (about 6kg/13kg respectively). The older one would probably fit the large too which we have but I haven't tried it as the medium fits so well.
How well did they fit?
Really really well! Particularly on our older boy, just like undies. We haven't had a poo incident yet but I think they'd do swimmingly (pun intended
What was good about them?
Side snap so any mess can be removed rather than smeared down legs with pull ups - yuk! Also snaps don't catch things like velcro can. Lycra so water flows through without pooling, has a mesh liner thing. Price also, I got them on special for AUD$12 each.
What didn't you like?
They're awesome, I like everything.