I'm not going to even try doing the math itself. It's just not my kind of thing. All I am going to add to this, is my own personal experiences and fuzzy logic.
This is my current raidbuild, and it took IAotH instead of Master Tactician. The logic behind that was simple. Fast attack speed, more autoshots/steadyshots, and thus more shots within a minute, capable of critting. From personal experience, this proccs
often. During a bossfight, this pops repeatedly. The problem, is that it is unsteady and unreliable. You never know when it is going to happen.
Sometimes, it proccs and proccs and proccs on every second autoshot in a row, and then leaves you hanging for a minute before you see another procc. Other times, it is quite steady, and stays up somewhat predictably.
MT on the other hand, sounds... iffy. 6% chance on hit? Even given Blizzards hidden Procc system (Crusader anyone?) it sounds somewhat low, given the increase. Consider yourself as a raidhunter. Depending on buffs, gear, groupsetup, you should have a fairly decent crit chance around 35-40% with decentish gear. This buff, gives 45-50%ish crit chance for 8 seconds. How many shots do you get off in eight seconds? Now say you get 10% of those shots as Crits, besides your usual crits. Sounds like a low DPS increase per talent point to me.
If you are worried about keeping EW up, it won't be a problem anyway. Once you got the gear to make EW worth it, you will have more than enough critchance to keep it up 99% of the time. And IAotH gives you that many more shots that can crit, as well.
I'd roll with IAotH myself. If nothing else, it reminds me to put AotH back after running around with AotV between packs.