I see it suggested in almost every build, but it never seems to do much for me.
In easier grifts that you can just kinda blow through anyway and TXs, enemies seem to die too fast for the effect to really make a diff. In higher grifts, it takes so long to go off that it feels like any other DPS gem would be better.
Is BotS just sorta lame post 2.4 now that it doesn't stack between players anymore and the snapshot was removed? Is it's one and only use to make RGs a lil easier and it's just subpar in any other situation?
Depends really on your class. I'll example how a wizard (myself) has used it. First off if its level 25 anything that gets close to you is slowed, that turns on the dps effect. I could use disintegrate using the passive temporal flux which says any arcane dmg I do slows the mobs. I could use Frost hydra, anything it attacks is chilled. There's handful of synergies that a wiz could use. The idea is to put them under a crowd control effect in order to activate the dps of BOTT.
Now I don't know the details of why use bott vs bots. I would have to guess it's more because of the 2.4 builds. Take the top wiz, it uses Slow Time, that bubble is effective to the whole grp, that bubble also produces crowd control effects. Likewise things die pretty fast in T10 that unless you are really struggling to kill things bots would likely never get a 30% bonus.