Which FRFR cab?
We've been doing this longer than most - the first Barefaced FRFR cab went out in 2009 (was that before most people called it FRFR?)
FRFR cabs are ideal for reproducing all modelling/profiling amps, any instruments that you'd DI in the studio because they don't need speaker colouration to sound nice, any acoustic instruments, vocals, backing tracks and recorded music of any sort. Basically they're like excellent compact PA speakers (which don't need a sub in the case of the 12XN models) or like very loud studio monitors.
The 12XN trio - for any instruments, however low they go!
Big Baby 3: This is the benchmark for high output yet compact FRFR cabs. Use it with up to 800W of power. 97dB sensitivity, so combined with that power handling it'll go very loud (126dB), keeping up in pretty intense rock bands for guitar, keys, etc duties. If you're wearing the bass hat (whether on bass guitar or not) you might need even more output (in the air-moving ability sense) if everyone is really cranking (metal bands, for sure).
Big Twin 3: This is two Big Baby 2 cabs in one box (without the extra HF driver/crossover). 1600W power handling and 100dB sensitivity gets it to 132dB max SPL. If you use this for FRFR guitar then your bandmates will hate you unless you know how to control your loudness. But it's a lot of fun having that much headroom!
Super Mini/Compact/Twin T: These three are not as hyper-accurate and don't go as low as the BB3/BT3. The Super Mini T has the least depth/weight/output in the lows. The Super Compact T has bigger and more accurate lows than the SMT. The Super Twin T is like an SCT+SC in one box. If the BB3/BT3 are too large but you need loud FRFR with the extra octave or two of lows that bass instruments demand, then the SCT/STT are more compact versions, whilst the SMT is even smaller/lighter than the SCT.
Barefaced AVD gone FRFR!
Reality 112FR: This unique cab combines the almost omnidirectional output of our AVD guitar cabs, that solves most sonic problems in gigging life, combined with the FRFR abilities of a coaxial F12-X200 12" driver, plus an adjustable rear-firing tweeter with its own crossover. We've called this AVD-8 due to the figure-8 full range flat response.
This is the way to go for all non-bass instruments unless you're playing very loud, very heavy, or downtuning a lot. It won't go low enough to do justice to bass guitar or double bass or synth bass but it'll make cellos or guitars sound great a fill a room in an almost magical way.