That one dead in the middle on the pics. from 5/1 looks healthy as hell! Would probably go wild if you transplant into a bigger container. Usually the fast-growing big ones tend to be males, but it would be lovely if it was a female! That's a nice bushy plant just like I like them. The others are looking good too but you are right, they look as though there may be a threat of becoming root bound soon. :-/ Hopefully they'll show some sex signs in the next 2 weeks. Now that I look at your most recent picture though, they are all looking nice. I hope you have at least 2 females.