I haven't used my pop in's yet but they seem very bulky, maybe to bulky for a tiny baby.
I have also brought some Bum Genius V3's that seem far less bulky. They are quite cheap at the moment as they are being discontinued.
I haven't got a tumble drier so I brought just 4 bamboo pop ins with the night boosters for night use, I then brought 6 of the Dream dri and 15 Bum Genius.
After much advice on this website I brought 2 brands, this gives you a chance to find out what works best for your bubs.
I do like the Pop In's though, other than the bulkyness they are cute.
Look on websites for deals, they maybe cheaper than in a shop. Fill Your Pants often has deals on Pop In's.