Pending on the drivers and the amps, more and more set ups are FL config nowadays. I have had both, and currently have 2 new FL cabs for 2 new and different heads. FL fills more space sonically, IMHO. And quite honestly, sparkle or at least seem a bit more alive than the RL's I've had.
Just my honest and humble opinion.
I am building a new extension cabinet with Alnico Golds in it, but as I'm hoping to recapture the essence of VINTAGE, I'll be rear loading these drivers. Otherwise, I'm sticking to FL for all other applications.
V.