Threat building, what's the better way to go?

Since one of my jobs in any raid is tanking (I'm not fortunate enough to be a dps only warrior, if that's fortunate) I am always considering threat amounts and searching for ways to do it better.

I've been trying an unusual Protection spec lately that seems to be working very well. Allow me to explain:

Gurggy's (12/3/56) Tanking Spec

This is a little different from most of the "standard" cookie cutter specs I've seen in that it

a) doesn't take Deep Wounds (although I've considered that too) but 

b) instead takes the Improved Spell Reflection and fills up all the prot talents we know and love.

First let me say a word or two about deep wounds.  Since the patch, I think it's fair to say that deep wounds is really only viably good if your weapon damage is good.  Not that my Red Sword of Courage's 240 avg damage is pathetic, but the ticking for 40 damage per second is less impressive than when coupled with the mighty BoH and it's whopping 750 average damage that ticks at 125 per second.   In fact, notice that even with the 2.075 increase to threat from defensive stance (even coupled with the .8 threat modifier from battle/berserker (not improved) stance) we have

40*2.075 = 83 < 100 = 125*0.8

so essentially, this talent will generate less threat for you than it will for dps warriors that are using a good slow 2 hander to cause their damage, even taking proc rates etc. into account, mostly because any good dps warrior should be far more "critty" than you anyway.

I exclude from this any discussion about attack power, since dps warriors should also have you beat in terms of attack power also.

However, it's companion, Impale, does something interesting for us.  Specifically in its synergy with Incite and Improved Thunder Clap.   So, here's the way this works:

First of all, Thunder Clap generates threat with a factor modifier of 1.85 * damage.  In defensive stance, you then multiply this by another 2.075 (assuming the standard method of dividing all threat by 100) [Source], and because of Incite you have a fairly high chance to crit when you do this.  It hits everyone around you once, and thus is very good for maintaining aggro with multiple mobs.  

Notice the entire effect here:

Threat of bumped Thunder Clap = (300 + modifier based on AP damage) x1.3(Improved Thunder Clap) x2.2 (crit + Impale) x 1.85 (built in) x 2.075 (Defensive Stance) gives us

(Dmg) x 10.979

If you couple that with Armsman enchant, you're talking about an 11.198 modifier to your threat from your base Thunder Clap damage when you crit, which you do 15% more often than you normally would.

Now, that part of that selection of talents may seem minor, but if you reduce the extra 20% damage from crits from abilities, those numbers drop to 9.981 and 10.180 with Armsman. 

That's a 10% increase in threat generated from an equivalently talented Thunder Clap without using Impale. 

I'm not even going to start in on the equivalent discussion for Heroic Strike, which you should be using whenever you hit Revenge because of the glyph.   Even though it's insta-threat isn't quite as dramatic as the Thunder Clap's, it's still a sizeable increase.  

So, while Deep Wounds is nice (and it is, don't get me wrong) the fact that it's tied to our weapon damage is part of why my threat generated from that ability wasn't even getting up anywhere close to the 10% of overall threat that it used to.  

Now, why take Improved Spell Reflect instead of whatever extra threat Deep Wounds would generate?  

Pre-Ulduar, the only time this talent came in handy was Eye, during phase 2 of Malygos.  Most of the rest of the time, bosses are attacking with area effect damage spells that aren't targetted, and therefore can't be reflected.  

However, in Ulduar, you'll find LOTS of places where mobs (even trash mobs) fire off spells that individually target people based on proximity, and in some cases, (for example: the displacement device which is created by these guys) the ability spawned "mob" can't be individually targetted, but spell reflect can hit and destroy it immediately, even when the tank is only close to whomever it is targetting.

I never heard so many people so happy about Improved Spell Reflect until I started raiding Ulduar.  

You don't really need every tank in your party to have this, so if you have 2 warrior tanks going along, and one of them has traded out for Deep Wounds instead, they'll produce maybe 4-6% more threat than you which will be really good for dps race bosses, but I would rather have the trade-off ability during most of the raid.  

I happen to be the only warrior tank that goes along on "most" raids, at the moment, so for me this is a no-brainer choice.  If we had another consistent warrior tank, I think I'd flip them for it.  After all, an extra 4%-6% threat is better than nothing.