I have used Bumgenius, 2 parts TotsBots Fluffle and I have tried the TotsBots Fluffle all in one.
My favourite is the Bumgenius and I hate the TotsBots all in one. It leaks, through the legs AND straight through the front, the fit and style is nothing on the Bumgenius.
Compared to a 2 parter, the bumgenius is a lot easier to put on and it dries quickly enough. It is a bit of a pain in that you really need to take the insert out before washing as I find it doesn't come out in the machine like the inserts do on the 2 parters.
I have not had any sort of an explosion with the Bumgenius, wee or poo.