"Don't forget that Mongoose scales with Kings, giving you 132agility which is 5.28% crit.
Since most Ret Paladins will not be stacking ArP because it's not as good as Strength, all you're looking at is a 5.6% increase in dps on Crusader Strike and Auto-attack when Executioner procs, as opposed to having Mongoose give 5.28% crit on all your abilities and 2% haste for your autoattack (and Seal of Blood, if applicable).
Every spreadsheet I use Mongoose always comes up on top, unless I specifically gimp my other stats to get more ArP, which is also results in lower dps."
**The Above is direct from Elitest Jerks forum. He makes the same arguement I would make against executioner he just does it with the math.
Really, STR scales better than ArP. Yeah, I'm sure in Sunwell gear you're being forced to take ArP items, but prior to that there is no reason to take ArP over either STR or Haste... That should take care of Mongoose vs Executioner
As for Mongoose vs Savagery
"Savagery Provides the best possible sustained (raw)DPS out of all enchants (PvE)
Agility gives you 1.4% more crit over Savagery, at the cost of 19 weapon damage.
Mongoose fails miserably on a slow weapon like DT. The proc rate grants 30 agility (1.2% crit) and 5.25% haste on average. Seems nice, but it's too streaky to rely on in PvP, and Savagery outperforms it in PvE."
**Again from elitest jerks, he left out a lot of the math but he's right. Sure, on a fast weapon where all u do is tank and spank the boss you'll get a lot of Mongoose procs but on any fight where you're running in and out or missing swings you won't have much of an up time on Mongoose.
Not to mention the fact that the average Ret pally swings once every 3.6 seconds. given Mongoose's average proc rate you really aren't seeing it up all that often.
This is why all 3 deserve 10's. Savagery gives the most bang for the $, and Mongoose and Execution are both extremely situational on which is better... Savagery may not be optimal for every fight, but neither are the other 2.