Leash - you know my favs are the motherease - but thats cos of the gussets - they are fab!!
Having said that, we use wool at night for Miss M now that she is moving more and we dont' get compression leaks - I also use bummis fleece ones during the day, some of maz's covers, but my favs are by far the mother ease!!!! But we do use the BB PUL ones, and she has a swaddlebees one on a the moment.

I think I like the ones with gussets more because if I haven't paid enough attention when putting it on (like DS is screaming in my face or something) then the gussets help protect their clothes if there is going to be a leak.