General

If u plan to pvp alot, max doom period. It is so fun to piss people off when they are pounding away at u and suddenly, they turn into a punching snail . If u grind at lhc or stronghold, max booster since doom doesn't work on pt play monsters. However if u grind on regular monsters and u don't have a familiar that recovers mp, max doom since u can take touch damage from the snails. And doom also changes elemental weaknesses (except heal where if u use it on a undead monster, u can still damage them with heal just slightly less damage).

Thanks for the input! I hit Bishop today and went with max Booster!

It's up to you to decide whether to max booster or doom. IMO doom is pretty useless atm

well, doom can't be used on bosses or boss-mobs...so if you plan on going to lhc or stronghold, it's just a waste of skillpoints

Thanks for the responses, everyone! A couple more questions:

So is Doom's only real purpose for pvp? How does it work in pvp- I've never done it before. Also, pvp is coming back, right?
And the impression I'm getting so far is that whichever skill I choose to max, it's not a huge deal, right?

I would max doom, because as a bishop with buff duration.
Level 11 Booster would equal out to maxed booster

I'm pretty sure leveling magic booster only increases the duration, but I'd max booster anyways.
Doom is just for fun really.

Isnt it lvl 11 for mages spell booster? Not 16?

I maxed doom, since buff duration means nothing when u got buff mastery in 4th job