Personally I’ve been rolling as Guardian as it’s pretty safe to pull a bunch of mobs and slowly bring them down to zero hp while ours stays full or almost full but the key word here being slowly.
Feeling like Balance is more flashy and fun but can’t pull as many mobs at a time without risking it too much. I am of course talking about sort of being on same level iLvl wise with content, obviously with very high iLvl any spec can roflstomp open world content with ease.
Depending on what I do, Guardian or Feral. If I’m pulling a lot, then Guardian, and thrash them down with Incarn. Perhaps weave in a HotW+Convoke. If I’m killing a rare, if it hits hard, Guardian, otherwise Feral.
If I’m doing easy stuff that doesn’t even scratch me, feral for speed.
But Guardian is my default for open world content. It’s not so slow, considering how big you can pull.
Guardian if there are plenty of other players around and I can pull big and let them dps mobs down. If there’s no-one else around, and nothing’s going to one-shot me, generally feral.