I use plain old Walmart Gerber prefolds and rubber pants, and have never had an issue with leaking or diaper rash or anything like that. My main issue is that rubber pants are really poofy and to me they just look kinda tacky.
I've made two covers from PUL with aplix closures but the closure part seems uncomfortable on my two very mobile babies, ages 9 months and 22 months.
What style covers do you prefer for prefolds (or flatfolds) and why? If your baby isn't yet on the go, I'm interested in your opinion as well because I have a new little one coming in October (yes three in diapers! eek!) and this will be my first baby started in cloth. I switched my two "big" babies to cloth just a few months ago. I can't afford to buy covers but I'm interested in looking at the ones you all like so I can try to make them myself.