Here is my list of pros and cons on the FS2000 (One of mine is for sale in the EE

)
Pros:
-Light (weight is not even an issue)
-Balanced (Definitely smaller in real life)
-True Ambi (Forward ejecting)
-Normal and Adverse gas setting
-Easy to tear down...up to removing the piston
-Accurate (1/2-3/4" @ 50m, Back up sights)
-Can be non-res
-Tri-rail available for front end (HUGE upgrade in both function and aesthetics)
-Clean shooting (no oils or fowling projected at the operator, all fowling restricted to the piston)
-Can fire A LOT of rounds before the piston MUST be cleaned (Due to adverse setting)
Cons:
-ONLY able to use USGI type AR mags!!(No Pmag, No Emag, No TD ARC etc)
-Hard to get a good sling setup
-NO bolt hold open
-The toilet seat cover is not bad but does add the extra step to a stoppage
-Piston is a very poor design. (Requires a special tool to remove when it finally is too dirty to keep working)
-Back up sights are a bit low for me. You really have to get your face down to get a good sight picture. Also the rear aperture is TINY especially for an emergency sight. Great for long range but crap for close up.
-Trigger pull sucks ass
I think that's about it. All in all, it's a good rifle. Well worth the look if you are interested. When my Tavor comes this week, I'll do a side by side comparison.
The issue of the lefty using the charging handle is the same as a righty charging an AK or a Sig...just reach over the top.
Those who don't like it's "curves" should check out the tri-rail front end. IMO getting rid of that bulbous fore grip is a definite improvement in the aesthetics department.