I wanted to start my own thread about the current possible configurations for enhancement shaman. I maintain that a blend of haste, versatility and mastery are the way to go rather than the "consensus" of stacking all mastery.
My build calls for the following stat loadout:
Haste: 13%
Mastery: 50%
Versatility: 27%
Crit: 18%
The gear available and current itemization may not allow players to get that exact blend of stats, but I can and I have been able to get very close to it.
Here are hypothetical "sims" based on the default enhancement shaman profile. Any changes I make to the profiles are noted:
1) Baseline profile sim with no changes:
http://www.askmrrobot.com/wow/simula...0da5e03eb65b51
258K DPS
2) Hypothetical (not possible) 77% Versatility / 0% Mastery
http://www.askmrrobot.com/wow/simula...af151a5aacb6e8
317K DPS
Point is to establish that versatility is the better stat IF it is available in equal quantities. Realistically, mastery is better because you get more % per point.
3) The default profile which chooses "Hailstorm" over "Ancestral Swiftness". No statistical difference from the base profile.
http://www.askmrrobot.com/wow/simula...c9c5aa131ae900
257K DPS
All things being equal, I'll take the haste because it makes for a much smoother gameplay experience.
4) The final sim is basically the default profile with stats overridden to match my suggested targets:
Mastery: 50%
Versatility: 27.5%
Haste: 23% (includes 13% haste from gear +10% from talent)
Crit: 18%
http://www.askmrrobot.com/wow/simula...ba5eccff8257ad
285K DPS
We can see that this is nearly 30K DPS gain over the base "optimal" spec that follows the "mastery is best" mantra, but more importantly, the benefits that versatility provides in terms of boosting healing AND damage by the same %, and reducing damage taken, make this a no-brainer.
I personally find that haste around 20% feels right, anything less feels sluggish and cumbersome, so once I'm there I'm free to pursue versatility, mastery, and to some extent crit. To get these numbers, you'll have to be a bit more deliberate about which gear you choose.
As for talent selection, it's the profile default on that website, except that I always go with rainfall - it's infinitely more useful than the "charge" or the speed-boosting totem. For arena PvP you may want to consider Ascendance over Landslide because with SB procs you'll end just anyone once every 3 mins.
Edit:
Here is a report that lists varying degrees of stat budgeting for enhancement shaman and the estimated DPS each combination would provide:
http://www.askmrrobot.com/wow/simula...d615c0378e21a9
While it does show an all-mastery build as being the top at 260K DPS, combinations in positions 3 thru 13 show that you can blend quite a bit of versatility into your spec at the expense of mastery or haste and still do a very competitive DPS averaging around 254K while gaining a substantial boost to healing and passive defense.
The question then becomes, is it worth trading 6-8K DPS for 10-20% boost to healing and 5-10% flat damage reduction? For me it's an easy yes.