Versatility is always a consideration because if the damage is close enough to other options, then you should always pick it for the damage reduction. And then obviously it just shines on classes with healing.
I just want to know what something like +80 vers does for apoc, all other stats being the same.
And I know I'm ignoring potential multiplicative effects - like having 100 vers and 40 mastery vs 60 vers and 0 mastery. But that's where you start to want simulationcraft or something for 20s, which we sadly do not have. Either way, multiplicative effects shouldn't be *that* pronounced at level 20.
Edit Caveat --> Sometimes raw damage isn't the most important thing, which is the point I was making above. Sometimes you're a Tow Truck and not a Formula 1 racer. Your engine being more efficient or w/e is not really relevant. You tow things. Unholy apocs healers. I want my apoc to kill healers. I don't care about my rBG numbers, personally.
I sort of hate the concept that we have in twinking of "Well, it's just a playstyle question" - because all that does is shift the goalpost to: what's the best playstyle? But there is some merit in the idea of what the purpose of your toon is. If you only do skirmishes or wargame arenas, your character should be geared fairly differently (for most classes) than for random BGs. In random BGs, you probably should gear differently for premading with healers vs. solo-queuing.
Personally I ignore all of that and just treat my wargame gear as being good enough for battlegrounds. If the average skill level of battleground players at 20 was higher, then I would probably get dumpstered in every BG for not having engineering. But I find it works out...