This question is always coming up on nappy forums and it's always divided. I think overall I prefer Aplix as it is more adjustable and so quick to put on but it isn't as pretty as a popper nappy. Also, my youngest DD tends to open her Aplix and take her nappies off but then DS pulls his side snap nappies down as those they were pants lol!
I did have an idea once that I would put the Aplix fastening at the back of the nappy but decided it was a silly idea. Then I saw on a US website a couple of weeks ago that someone already has and it makes perfect sense
Sorry to ramble...