I was thinking about starting a thread on how this FP was too easy for me when I saw this discussion. Level 50 in PvP gear, are you serious?
There was one wipe for us during the cannon part which happened, to be honest, because I got too fascinated with shooting this fine weapon and completely forgot about what I should be doing i.e. healing.
On the second go I occupied a strategic position atop the big box in the middle and concentrated on restoring my group mates HP. That was some pretty intense healing session, at one point I almost lost one of my mates but, thanks to the newly acquired resplendence, it all ended well. All in all I`d say the turret part of the FP was just right. It was hard enough to make it interesting but not hard enough to make it frustrating.
After that things got a little... silly. Mobs did little to no damage, including elites and champions. There was almost no need for my healing untill the very end when the final boss used some AoE, reducing all of ours HP in half. This impressive feat prompted me to say to my group mates something like: "Finally some challenge!" But before I could finish typing... the boss died.
In conclusion I can say that in my opinion difficulty of the turret part is ok, difficulty for the rest of FP should be increased SIGNIFICANTLY. It was easier then some of the solo missions (in particular the class quest on Quesh which I did at the same level) not to mention heroics...