I've been out to the range now 3-4 times with the FS2K. I've run about 150 rounds through it. Just like everyone else has reported the trigger pull is quite heavy and gives you a work out. I haven't done anything to it other than clean and lubricate the trigger group as part of maintenance. I probably will try graphite to this area as someone else suggested.
The first 60-80 rounds I had trouble with double and sometimes triple feeds with Radway Green 92 surplus ammo even with the gas selector at the adverse setting. Very frustrating and made me question my purchase! I tried some Hornady TAP 75gr ammo in it also in that group and even that had some feed problems.
The cycling issues have improved with the last 60 or so rounds. I shot an entire magazine of the same RG ammo without a double feed. The Hornady TAP ammo worked without any problems this last trip to the range. I even tried some of my reloads and they seemed to work pretty well as I shot it more.
With the heavy trigger pull it is hard to be accurate, especially shooting off hand. On a rest using my eotech 553 the best I could do was 6" 3-shot groups at 100yds with the TAP ammo. Maybe it's me. Off hand I could just do center of mass with the eotech.
I tried a burris 3-9x scope on the gun on my initial trips to the range, but it didn't feel good so I switched to the eotech this last time out. I like it much better on this gun. The iron sites are adequate, but kind of cheesy considering the cost of the gun.
My sense is with more shooting it will get smoother and more reliable. I wish the trigger pull was lighter since really that is my biggest complaint.
I bought an offset picatinny mount to attach a TLR-1 tactical light just above the charging handle on the left. I'll post a pic of that later. I got it from "cheaperthandirt.com". It's not in the way and is functional, just not very sexy. I just ordered the ERT sling for it after watching the video. Another accessory I would consider for it would be one of those Grip Pods if I could get a short piece of railing to fit on the under side of the fore grip.
Now that it's shooting better, I feel better about my purchase. I like the length and balance of the gun, but I wouldn't feel confident about long range shooting with this the way the trigger is now.