Ah very interesting thread!
TL;DR: I can confirm that the FAS doesn't feel half as awesome as it used to.
As a FAS owner, a year ago, I used to feel awesome in HazRES and CZ... Then, a little bit before The Commanders, I went doing some exploration, then after a couple of months of exploration, I've had to make a break from playing ED until july.
I decided to go raise my combat rank as much as possible (I'm currently "deadly", and at the time, 18% to Elite, or so)... So I undusted my FAS, engineered it a little, took a massacre a mission (50 kills+ to do) and jump into a CZ... After 2 minutes, my ship exploded (it didn't help that a Federal Capital Ship stripped me of my shields on arrival by bumping me accidentally while coming out of hyperspace). I managed to complete the mission, but I had to do several runs to the repair stations to do so.
I was back to being a total noob against those happy railgunning NPCs! I was able to improve nonetheless, and make more runs, but the conclusion was my FAS shields were too weak for my fighting skills at least in a CZ.
I had thought I had got too rusty, but reading this thread is confirming there's been some buffs and nerfs I hadn't followed...
So I might go back to the Vulture; I have fond memories of flying with it and you all say it still rocks as it used to
Then I will upgrade to the FDL.
Conclusion: I can confirm that the FAS doesn't feel half as awesome as it used to.