Here's my recent experience w/the STG-556:
Just received my STG-566. Based on the listed pic it looked like I was getting an older version (tulip FH, no BHO fence, fewer QD sling positions) but when it arrived I was very pleased to see the new style FH (which I prefer) and the BHO fence. While I would have preferred green I must say the black version is *very* good-looking, the epitome of EBR.
For the optic I decided on the Aimpoint CompM4, not only because it uses the same AA batteries as the rest of my kit but also the included QRP2 mount can be reversed so the QD knob is on the right (instead of the left) so it won't interfere w/the STG-556's left-side charging handle. It's mounted far forward to minimize the Aimpoint body's perceived size while aiming and to leave space on the rail for an upcoming experiment: LaRue Po Boy Special w/the Heinstoldt 2.5x magnifier. I added a 3" rail (from Promoted Pawn who advertises here, an excellent piece of gear for a great price:
http://www.microtalk.org/viewtopic.php?f=8&t=201 ) for attaching a Streamlight TLR-2 combo taclight/laser w/remote tapeswitch held in place by Ranger Bands and a Gear Sector Gen.II ASP single point sling adapter (I'm not using any of the STG-556's QD sling swivels at this time). With the TLR-2 far back on the rail there is some bbl shadow at 10 o'clock but it's not severe and is pretty well filled-in w/scatter. An advantage to having it far back on the rail is that both the constant-on rocker & mode switches can be reached w/the trigger finger w/o changing my firing grip (and moving the TLR-2 further forward doesn't improve the 10 o'clock bbl shadow).
As w/all new firearms, first thing I did was strip it down for a good cleaning/lubing. As forewarned, I found the disassembly latch was extremely tight the first time but is improving w/usage. Takedown was quick & easy (except for the aforementioned tight takedown latch) w/relatively few parts & a bolt assy that's *much* simpler than the FS2K's bolt assy (my biggest complaint about the FS2K is the complexity of the bolt assy). Cleaning/lubing took little time (much less than the AR's I used to own) and it went back together easily (yep, RTFM!)
Anywho, headed out to the range w/the STG-556 and a friend's FS2000 so I could do a side-by-side comparison. Ammo used was Wolf poly 55gr, Silver Bear 62gr & Prvi Partizan 55gr.
I initially sighted in the STG-556 w/the Silver Bear to get me on paper then finished sighting in w/the PP 55gr. Lo and behold, an interesting development!: the SB's POI is exactly 3" to the left of the PP's POI at 100yds! (Someone suggested this is due to barrel harmonics but while I've experienced vertical dispersion of POI's caused by bbl harmonics this is the first time I've ever experienced horizontal dispersion of POI's!)
The trigger pull of the STG-556 is horrible for precision aiming! I'm hoping this will improve a bit w/time or discover a safe method for improving it but as-is it's just fine for the CQB tactical shooting I do (in fact, I prefer it to the FS2K's trigger for that kind of shooting).
Handling: This is a pretty subjective area but I find the STG-556 just plain handles better for me (YMMV). It's faster on-target and doubletaps are faster/easier as well when compared to the FS2K. Mag removals aren't bad but I'm obviously going to have to practice or learn a new technique if I want faster reloads! The forward assist and bolt hold-open don't bother me in the least, in fact I usually don't know they're there.
I ran a couple of tactical drills as well as some informal bouncing of several empty milk jugs. While the FS2K handled better than any of the AK's/AR's I've used in the past it still didn't handle as well or as quickly as the STG-556 (this could be due to a number of reasons that are directly shooter-related as well as obvious possibilities like the FS2K not having a vertical foregrip like the STG-556).
Functioning of the STG-556 was 100% for the couple of hundred rds fired except for the first time I tried the 42rd mag when I got several FTF's. This I attribute to operator error while loading as loading it more carefully resulted in no more problems (and 0 problems from the 2nd 42rd mag I tried), the 30rd mags were all 100%. Btw, I really like the design & quality of the MSAR mags, not only are they shaped well for handling but rugged as well (I accidentally dropped a fully loaded 42rd mag onto concrete and all it did was spit out the first 2 rds).
My biggest complaint about the STG-556 is the charging handle. While more rugged than the FS2K's (which have been know to occasionally break) it's also more difficult to use. Not only due to the shape which requires turning the offhand palm up and engaging the charging handle w/the little finger but the springs are stronger as well requiring more effort to manually cycle the action.
Overall I much prefer the STG-556 over the FS2K for my needs (YMMV) but so far both have been 100%.
Tomac
STG-556 Right Side:
STG-556 Left Side:
Aimpoint M4 Setup to Clear Charging Handle:
3" Rail for Taclight Attachment:
Better View of Gear Sector Single Point Sling Adapter:
Gear Sector ASP Single Point Sling:
STG-556 & FN FS2000:
