Buttons Diapers covers are excellent quality. Buttons have a double layer of stretchy, waterproof PUL and double gussets around the legs (useful for keeping stuff inside). They’re an All-In-2 (AI2) system that has a snap-in insert feature. This particular insert is hemp/cotton (very absorbent) topped with fleece (moisture wicking).
Buttons sells a microfiber insert, but I never recommend microfiber; it tends to develop a stink that won’t go away and doesn’t tend to last more than the diapering life of one child. Buttons also has a night-time insert. Additionally, Best Bottoms inserts are interchangeable with Buttons (they are very nearly the same diaper).
Some people complain that inserts like this (as well as pad folded prefolds and flats) bunch up in the middle on mobile babies and absorbency is lost. But, you can use Buttons covers with any type of innards, not just snap-in.
A review by a Babycenter mama gives Buttons 4 out of 5: Great Covers Comparison Buttons