I would do a Google search as there is lots out there that doesn't need restated.
That said, my biggest complaint is the pinned factory comp. And parts are harder to find, but FN will take care of you if you run into any problems.
Other than that, I think it is handy and it never felt bulky to me. The front ejection is cool, especially for dexterity. The tri-rail is a must, and is cool with a hand stop or an AFG. The downer is that the charging handle is not reversible if I recall correctly, so lefties have to charge it AK-style. The charging handle doesn't reciprocate, but it also doesn't lock back on an empty mag.
To this the day, it's the only gun I regret selling. I did get a SCAR 16S with the funds, which is more customizable and is the bomb as a SBR.
As far as bullpups go, the FS2000 is the only one I have an interest in. I think the Tavor and the AUG are a tad more customizable, but there's just something awesome about the tactical tuna.
Whoops, looks like I ended up restating stuff anyway.