lol, I was going to say we've stopped using the one with a slot in it cos JJ makes a game of trying to get his foot through it. In fact we've stopped using ours altogether, although may revisit that when the weather gets colder.
Definitely being able to unzip the bottom for ease of nappy changing access is very useful. In desperation a month or two ago, when we were still using a sleeping bag as a way of weaning him off wrapping and I didn't have a summer weight bag, I just cut a neckhole and armholes in the top of an old pillowcase and it worked great!
Since we're not using ours at the mo I'd be happy to send you a couple for you to try on bubs and/or take a pattern from, as long as you don't mind popping them back in the post when you're done, or I could bring them along to one of the weekend catchups if you're coming to any (eg Cheltenham on Sunday)? Drop me a PM if that would be helpful.