I have started to have this exact problem. I hate fitteds, too, BUT it's the only thing working. He just has to have full coverage of an absorbent material. The combo I use to hold my super heavy wetter over night are: Tinkle trap pre-fitted with doubler, tri-folded Thirsties hemp size 1 prefold, Flip stay dry insert. I either put a PUL cover over this or a fleece soaker. This combo is very wet in the morning, but is the only thing that does not leak.
Happily married, Mom of C (15), M (3), and E (1). Expecting a very big surprise baby on 3/25/14.
WAHM of hand-embroidered creations in my Etsy shop here.