I'd argue that there wasn't really choice in BC. Stack spell/attack power on all gear, use cookie cutter build. Go for x best stat. The gear is the same, they've just accepted it and stopped making crappy drops without mainstat that nobody would use.
"Rotations" as a whole are more complex now, so that they're not even rotations any more. They're priorities. For example, on my Shadow priest, I need to
Keep DoTs up
Use Mind Blast on cooldown
Use Devouring Plague at 3 shadow orbs
Mind Flay as Filler
Shadow Word: Death when <25%.
On top of that I have to also compare my active DoTs on the target to what I can cast with my procs up
Refresh DoTs before casting Devouring Plauge if procs allow so that I can maximize Insanity Channeling
Use Shadowfiend when it comes off cooldown.
Watch for low-health mobs I can snipe for Twist of Fate (and then refresh DoTs on my main target again).
And that's just for single target using my preferred talents. If I switch to an alternate build using
Divine Insight as opposed to
Twist of Fate I have to also watch out for Mind Blast procs and use those immediately. DI vs ToF is pretty much equal in terms of DPS, especially on single target and whichever is better is really debatable (especially once you take set bonuses into consideration) so I can really use whichever I feel like. The alternate to Insanity is also close in terms of DPS, so I may use that as well.
And as for choice in gear, this is kind of new to this tier but for Shadow at least, I can take essentially any kind of gear I want and use it well, as long as I meet certain requirements. Haste is great up until one of two caps (I choose which), at which point Mastery and Crit are relatively equal and I may gear for whichever I choose or any mix of the two. I can go for a haste cap at which Devouring Plague gains an extra tick, or I can go for the GCD cap at 50% haste. After that, I like a mastery heavy build myself, but for my spec Mastery and Crit have a really cool relationship that makes them relatively equal.
Add in stuff like
this trinket, and it makes theorycrafting a HUGE pain in the ***, but also fun if you're into that. It's to the point where the guys over at the Priest forums use a specialty-built computer they call the "Blowtorch" to figure out the best ways to maximize DPS.
So no, I'd argue that MoP theorycrafting is much more difficult than in BC, and choice has only improved. In fact, I'd say that one is directly responsible for the other.
Edited, Nov 22nd 2013 6:55pm by IDrownFish