Our stash is almost exclusively fitteds (we have a few AIO's for when ds wears jeans). The benefit to fitteds is that they are cheaper than AIO's, you can use wool over them instead of PUL (ds got heat rash with PUL) and in most cases they dry faster. In an AIO when the PUL wears out thats it, the diaper is done, with a fitted if a cover wears out you just buy a new cover (but wool wears a very long time, I've never had a wool cover wear out on me). And you can do fitteds under longies (wool pants) with no cover. And some moms enjoy allowing their children to run coverless at home and just changing as soon as they are wet. It lets the tush breath and allows you to know the second your child wets (good for potty learning). Now prefolds are cheaper, but they are a bit harder to use, they aren't as absorbant (depending on the brand of fitted anyway) and they usually aren't as much fun. Prefolds have a specific somewhat bulky shape, and alot of people find them incredibly intimidating. I have been cding for 4 yrs and just learned to really use a pf, and I am not super at it, dh won't do one at all. Also you can get fitteds in a one size system allowing you to go from birth to potty learned in the same fitteds, something you can't do with prefolds (some AIO's and pockets come in OS systems, but in my experience they wear out before the baby potty learns). The MEOS's for example can make it through multiple children birth to potty learned (though alot of people find them really bulky on tiny babies). Anyway in 4yrs I have used pretty much every system available. In the end I found that I really prefer fitteds and wool to any of the others. It isn't the simplest, but not the most difficult either. A nice middle ground, and so cute and fun to experiment with.