I moved from an Ampeg SVTIII Pro & 410HLF to a BFS12 with the SVT - the amp in a rack with wireless rack was heavier than the cab!
Didn't get on with the SVT/S12 combination so got an OTB500 and can honestly say it's the best sound I could ever hope for.
The HLF is thunderous in the low/low mids - so much so I was rolling everything back and could never nail the 'sweet spot'.
When I got the S12 I thought I'd have to bump the lows up again but, no, the S12 threw out as much low end (and better controlled) as the HLF with all the mid drive, which, IMHO, the HLF couldn't do - it was too wooly and the tweeter only made the scooping sound worse.
I didn't even try an OTB until I got it - just took onboard all the reviews on here and went for it. I got a sound in minutes and I've not deviated much from that 1st five minute set up - the SVT had so much scope I was always fiddling with it and never really happy.
I am now! And I can carry everything in one trip - amp/cab/bass/gig bag.
I can't see me changing my rig [s]for a very long time[/s] [b]EVER![/b]