They launder really well. They're durable. If you buy bleached you can soil to your heart's content and then bleach them when you want them looking their whitest again (or try sunning them!).
We have over 2 dozen prefolds that Rowan wears every now and then. I have a pretty large stash so admittedly we don't use them as often as the pockets, but I love my prefolds.
Currently Rowan is about 16 lbs and almost 4 months old.
She is outgrowing her clothes and diapers like crazy now.
In her "currently fitting" prefold stash we have Bummis Organic Cotton Infant prefolds (7-20ish pounds) and Medium (Yellow edge) Smart Fit Imagine Prefolds (12-25 lbs).
Bummis infant prefold on top of an Imagine medium prefold.
Rowan barely fits in her Bummis infant prefolds now that she is 16 lbs. I could see these fitting her snappied for maybe a pound more, but not longer than that. Trifolded, though, I think they might work until 20 lbs. The problem with that is she is going to outgrow her small covers soon and in a medium cover there would be less coverage.
I used these since she was about 11 pounds. They are super soft after prepping and fit beautifully in various small covers. The best deal is to buy a Bummis Diaper Kit and get a bundle of prefolds, covers and a fantastic wetbag for less than $170. Then sell all of those and size up when needed! You know me though, and I probably wouldn't personally drop that much money on a small stash, but I'm cheap like that. For people with some common sense it is a great buy, though, because the covers and prefolds are of great quality.
Rowan in a Bummis infant sized prefold, snappied. She is 16 lbs here.
The Imagine prefolds we have (medium size) I anticipate will fit us for many months to come. They are wider than most prefolds so they will be a lot easier to snappi, a problem I ran into with Chinese prefolds for sure and even GMD prefolds after a while.
Rowan in a medium Imagine prefold from Nicki's Diapers.
There are a variety of covers that I love and recommend for the "infant" stage but the ones I most often use are my small Bummis covers and my small Thirsties cover.
I can use both my Imagine prefolds and my Bummis prefolds, either snappied or trifolded, in either of these covers.
Bummis infant prefold trifolded in a small Bummis Super Whisper Wrap.
Bummis infant prefold trifolded in a small Thirsties cover.
The Imagine yellow edges can also fit in the same covers! The fit would be a little bulkier, though. Just to show that if you only have larger prefolds to work with you CAN fit them trifolded in a smaller cover.