I tried a Well-Fitted medium armor build last night because I'm tired of having to run Impenetrable all of the time to stay alive. I thought it would be fun to run around roll-dodging, but I quickly discovered that in this undodgeable AOE meta, a build without much crit resistance (all I had was 38 CP points into crit resist node) gets massacred.
I'm currently going to make a run at 5 pc Impregnable for the time being so I can avoid Impenetrable, but it seems like something is wrong when I have to use a 5 piece set just to feel comfortable using other armor traits. Is Impen too necessary in PVP? The only players I have talked to who don't use Impen on some of their builds are either shield-stacking or ganking/bombing, everything else is at least 5 Impen.