I started with these prefolds and vinyl covers (!) and moved to pockets with the prefolds as inserts. I always had to use double when I stuffed and definitely not overnight. They absorb quickly and fill up quickly. I loved that there were organic Gerber prefold options. And they were pretty darn cheap.
I did end up buying microfiber as well as natural fiber pocket diaper inserts to use when my son got bigger. They added absorption to the standard inserts. I don't think you can full time diaper with these unless you have one hundred of them and triple stuff with wool for overnight.