Aren't all but one of them passives? I thought only the tier 5 ability was a clickie...
You're probably right, but if they keep adding clickies for every rep system things are going to get ridiculous. I already spend the majority of pvp matches looking at my cool downs.
The Somraw, K'tinga, D'Kyr, D7, Kumari, Xindi carrier, Xindi escort, and the T'Varo are all older than the Constitution Refit and yet they are tier 5. The Constellation is made up primarily of Connie refit parts and it is tier 5, there is no logical reason whatsoever for the no tier 5/6 connie rule.
Sadly the Reman set still doesn't seem like it can compete. The stacks still don't refresh so the stacks are essentially fighting each other. 2 is the same as none and 3 is the same as 1. If they refreshed so you stopped getting heals but kept the capacity to heal into it once you hit max stacks then you'd be talking.
Currently it's probably the best shield if you're only getting shot at from one side and you can keep TT up. Those shield procs will get funneled into the appropriate side and once the side that's not taking damage is empty there's no downside to the stacks expiring.
For the rest of us that get shot at by more than one person, it's not so hot. If you see the shield proc and a TT on somebody then whatever side is getting redistributed away from is about to show you some hull.
This is just my impression from PvE on tribble, the Reman 3 piece proc under a coordinated alpha might produce something entirely different, like the unintended BFI effectiveness.