im feral druid as u can see from topic name!

im the tank in most instances with my friends.
but i love to do pvp too!
so now i wonder if Survival of the Fittest is rly so important as a tank or can i live without it??

can u tell me your experiences with primal tenacity. does it proc often? does it rly help? 15% is not that much is it?

so plz give me some advise!!

SotF really helps a lot when tanking. Without it you need 75 additional defense. That is around 180 defense rating.
Of course if you only tank non-heroic 5-mans you don't need to be crit immune.
The 3% bonus on all stats is not to shabby either.

The 15% additional resistance Primal Tenacity gives you helps when tanking, but not much. Basically you resist one fear out of seven. In PvP, it is great.

So if you do not plan on tanking any hard instances and want to do a lot of PvP it should be no problem to go for Primal Tenacity.