Hi Liz
I use Bumgenius V2's for DD who is now 6 months, I think we started using them when she was about the same age as yours.
I can only tell you what I do with V2's as I haven't seen any V3's but I can't imagine they are that different.
I washed mine twice with one tablet and no sofener. Tumbledry for about 40 mins or radiator dry, they dry very quick, but you need to undo the popper on the insert or they don't dry properly!
I keep the poppers on the outer fastened all the time, even in the wash, you don't need to undo them they wash fine fastened up and she is on the middle size at the moment, the insert is poppered on the middle one to. You don't have to undo the poppers on the outer bit to stuff them, I fold the insert in half at the front and then stuff them in, it is fiddly to begin with but it does get easier and faster! I then flatten them out with the folded over bit at the back, I found it a bit bulky if the folded bit was at the front?
I have microfibre boosters but to be honest have only used them a few times as I find the supplied insert enough. I do change her about ever two hours, more if she poo's obviously! The pocket has never filled with wee in my experience but the insert will get soaked if not changed regular.I haven't used them at night yet, I'm afraid I use a sposie, but let me know how they last overnight!
I've got the pink ones and they are adorable, everyone comments on how cute they are and having used Tots Bots before they are far easier and more reliable! I ordered twenty on a BOGOF and wash every three days!
One tip though, never wash them with more than one tablet or half dose of powder, they foam up so much my washer wouldn't drain!! and don't put softener in it affects the absorbancy.
I've just read this back and I'm such a Bumgenius bore ........... sorry but I love them!!!