Is it worth it to get the i55 PvP gear as a tank?

I've read numerous threads but they all seem a bit outdated since there was no i100+ PvE gear when those threads/posts were made.

Also, is the i70 PvP gear worth it (as a tank)? It seems to take a while to get to rank 30. Might as well save your WM and spend them 8 ranks later for i100 PvP stuff, or..?

Your thoughts please.