I don't see any downside to micing a bass cab. And vs DI it's really just a matter of preference and/or convenience.
Usually, yes. It's most often a wash if you're aiming for clean tone in the FOH and you run a pretty clean & even stage rig.
Sonics can favor using the DI if you want a clean & even tone in FOH, but you've had to significantly eq your stage rig to more effectively monitor on a very loud or bassy/subby stage.
Sonics favor a cab mic if the cab's high and low end roll-off are part of your sound (say, if you're after the sealed 810 vibe, or if you run OD and distortion—which can sound ganked if not low-passed where you want them.)
If FX play a key part of your sound, sonics rule out taking DI directly after the instrument. Similarly, sonics call for post-eq DI from your head or rack if you've dialed that part of the chain specifically for FOH feed—esp. if you have eq later in the stage rig chain that lets you tweak your cab sound to deal with oddities in the stage acoustics.



