Shorter overall length, so longer barrels or suppressors can easily be accommodated.
Recoil directed along axis bore through butt, less muzzle flip.
Do not seem to “balance and handle” as well as conventional designs. May simply require familiarization.
Minuses of Bullpup design:
Much longer trigger linkage, more complicated design.
Muzzle is much closer to operators face(unless barrel is lengthened).
Sights are much above bore axis (not so great for hunting guns that require precision at shorter ranges).
Do not seem to “balance and handle” as well as conventional designs. May simply require familiarization.
Puts most magazines in the butt, not as easily accessed by dominant hand as magazines near the trigger.
And your point, the ejection of empties occurs nearer the shooter, so it must be dealt with. If done well, this is not a problem, but it can be. Empties can be directed downward, or switched from side to side, or as in the Kel-Tec, even pushed forward and out a tube (fascinating design!)
Thx for the bullpup analysis!