We love ours. We used the newborn ones (which fit until nearly 6 mos) and were so happy with them we got size 1, and now size 2 (they've since changed to just the M/L). I just really like the snaps, and they wash/wear super well. I just took the newborn ones out to use again next month and they barely show any wear (one of the reasons we wanted fitteds is that we knew we'd be having more than one kid). They are NOT an overnight diaper.
That said, I looked at the new M/L in the store, and I cannot imagine putting that on a 15lb baby. It's a lot of diaper.
I recently purchased a Kissaluv 2.0 fitted size M/L for night time and I?ve had great results with no extra absorbency added. I will be purchasing a few more.
I'm a big fan of the KS 0's. Runny poos just can't get past that fleece-y cotton. If I have a second baby I would love to have 12-18 of these in my stash.
I agree with the PP who said they are not an overnight diaper. But at the newborn stage you are changing them so often it doesn't really make a difference.
The size M/L's are huge. DS has definitely outgrown the size 0 but is not ready for the M/L. I got the M/Ls as contours (w/o snaps) because DS was in between snap sizes for a long time with the 0's. Hopefully I'll be able to fasten these with pins or a snappi when DS is bigger.