JTR- I would agree with OBER & CAMPY's assessments. When I was in the Army it was comfortable to patrol with a vert grip. When wearing armor and a LBV it is fairly comfortable to tuck in the elbows and keep the weapon tucked into the pocket of the shoulder.
When doing prone IAD's the magazine gets in the dirt (AK or AR) before the vert grip will, so just tilt the weapon to its left side, ejection port up, to fire. When firing from a bench, then it takes getting used to.
Other than that, the only people I saw that actually had a standard use for it were the "Special People" who use it for weapon retention & during weapons strikes. It is amazing to watch the abuse that they put their weapons through! It was related to me that the vert grip allows better PUNCHING/STABBING force but it takes training. Look at the DEITER grip, (sold by MSTN) it is the evolved "TOUGH Mo-Fo" grip specifically engineered for their demands.
Having a vert grip does have its ups and downs. Most of my long arms have them, as that is just what I am used to.
If you like it, go with it. Unless it is against some departmental or unit SOP, do whatever you want! That handguard is a quick swap out, so if you don't like it, take it off and put in over in the Equip.Exchange forum and sell it or swap it for something else!