I've only been using Rumparooz for a few days, but so far I'm very pleased with the results. I think I will be buying several of these for Emmett and Mimi. Unfortunately they are shockingly expensive but they work well and seem the most comfortable. I was very worried about the bulk but once it's on the baby and then you switch to the less bulky BumGenius 4.0, it really isn't THAT noticeable.
The BumGenius 4.0 is probably my second favorite so I plan to buy a few of those as well. It's second because the insert moves around a bit more than I would like. It hasn't been enough to cause problems though and I love that they fit a bigger baby so well.
Rumparooz though, I have to say, I'm impressed. They are the ONLY diaper that will fit a newborn (we'll test this out in October) AND my 2 1/2 year old toddler. BG is too big for newborns, fuzzibunz is too small for my toddler (she can wear it, but it's snug) --- every diaper I try it is either one or the other, but Rumparooz fits all sizes. We'll see though, I could change my mind after trying them a bit longer.
Also, the first thing I noticed about cloth diapers is that my daughter is more aware of when she's dirty. I really think this will help her potty train faster. As soon as the diaper was heavy with pee she immediately came to me fussing to be changed. She would have never done that with a disposable diaper.
Good results so far!