Mainly though, that build has much better agro thanks to having Surge and Pact Conversion. I use this build on everything except the most difficult boss fights.
Keep in mind that without 38 reaver your basically making yourself a bland tank. Unfortunately tank speccs in the game aren't very good except for 38 reaver. Take that away and rogues can be considered superior tanks to warriors.
None the less if looking at other tank trees Your best bet really depends on the fight. 20 Warlord is a good investment with the synergy crystal just due to the fact its easy to apply and applies good mitigation so your going to want that. As far as going 'non reaver' your best bet probably would be pally... which honestly isn't all to great. It has some good physical reduction but it falls quite behind in other areas, but it has the most potential for holding through and tanking I believe of the other trees.
VK right now is a good disruption class in pvp but a terrible tank specc. It lacks mitigation and is probably the worst possible tank specc to play in game, unless your talking about some crazy build. Even with a heavy magic damage fight it loses out a lot.
Warlord is pretty useful utility wise but after 20 points you will find yourself applying things that other classes will apply that should already be in the raid. It has better tanking power then VK and group support but its not going to be a great choice in many cases unless your maybe lacking an Archon.
Hopefully they do something to buff the warrior tanking souls so it doesn't feel so limited in options or you gimp yourself.
Reaver > Void Knight > Warlord > Paladin.
None of Warlord's pre-20 stuff is going to work in a Raid, with the exception of Cutting Distraction. Some of the level 28-32 abilities will work in a Raid - only one of them is overwritten by an Archon ability, I believe it is Assault Command but I'm not sure on that. Call to Battle/Spotters Order/Call to Entrench are all going to be overwritten in a Raid setting.
Paladin gets by okay as long as there is no magic damage. His physical mitigation is actually pretty good, assuming he manages to block. However his magic mitigation is lacking by a huge margin when compared to the other three tank specs.
I would argue that even 38 Reaver is a bland tank spec, because it doesn't get any of the coveted 44-point cooldowns. None of our "equal to Justicar" specs do. That's where Trion has screwed us most blatantly.
Blood Fever will apply the DR from Binding of Death and also the 5% reduction in chance to hit.
No Quarter #1 NA
1. Reaver is the only tree that gives us mitigation for spending more than 26 points.
2. The amount if mitigation in each tree is unequally distributed. Paladin only gets 3% to magic. Warlord 6% to all, VK 8% to all and another 3% to magic. Reaver, for reasons unknown, gives 19% to everything. Meaning spending 38 points in reaver is better than 16 in WL AND 26 in VK AND 15 into Paladin (minus gift effects).
3. Paladin gets physical mitigation through unyielding defense, which is more OP than BoD in some ways. The problem is it requires you to block.
The net effect is that non reaver builds cannot match up for magic defense. The only way they even out for physical mitigation is through UD. On average you take about the same, but when you don't block you get hit 20%+ harder.