I currently Main Tank with
http://www.wowhead.com/?talent=sZ0tVAbuMteIRhots0xb and have had no issues with my current gear. It might be important to note that I did not make the switch from 5/60/6 until I had all the gear I currently wear.
This question had been asked several times in the talent spec section of the forums, but here is the skinny on it:
Seals of the Pure is not terrible and it is not great. I think that either going deeper ret, or using the 5 holy is a matter of personal preference.
JoJ definitely works on boss mobs, and I still choose not to take it. i very rarely will be in a raid without an offtank, and all of those offtanks have the a similar ability that does not stack. More often then not, my current 2 tank is a DK, and he puts frost fever up on bosses that i need it.
This is not to say that there are not rare occasions where it would be handy to apply a debuff such as this myself, but would not make the difference between a wipe, and getting a boss down. Since that is the case, I like being able to run faster and crit more often. 27% crit raid buffed + the debuff from HotC is nothing to sneeze at. Especially if you abuse Shield of Righteousness Rank1 like I do =P. I am not sure I want the 1 point I have in benediction vs the extra point in imp judge, which would allow greater uptime on libram of obstruction, though a less than optimal rotation.