I see it as a matter of diminishing returns. If you're really keen on the feeling of bulk, go for it, but layering two thick diapers and poking holes/cutting slits isn't going to last as long as those two used in succession. I find it also raises the likelihood of leaks overall. Stuffer pads generally work better if you don't go overboard with them as well but sometimes it's just a matter of what feels right. Experiment and find what you enjoy.