Loved the lil joeys and BG NB XS diapers for DS. No leak issues with either, unless I left him in them for too long (like a couple of times when I was stuck in traffic). They stayed relatively dry against his skin, whereas he howled every time he was wet in a prefold or in a fitted (nice in some ways because I knew he needed changing, rather than having him sit in his own pee, all damp like he would in a sposie). Also tried simplex NB and applecheeks size 1 but found they both wicked so sold them off.
He lasted in his NB diapers until about 12 - 13 lbs (so about 6 weeks) but was fairly narrow at the waist. I'd second the recommendation to buy them used - you only need them for a shirt amount of time and most of the used ones have been used so infrequently that you can get them in good shape.