What do you want to use it for? Personally, I wouldn't have much use for an AR-15 pistol other than target shooting, or just because I think it would be cool to have one. As a pistol, the gun isn't really good for anything that I would want a handgun for.
For self defense, a .223 is not the best gun, and a pistol version wouldn't have nearly the muzzle velocity or accuracy of an AR-15 rifle. It would defenitely be more manageable than the rifle and would stop a would be carjacker in a hurry, but so would any good semi-auto pistol or revolver in a serious caliber. Shooting someone who tries to jump in your car at a city intersection could potentially endanger a lot of innocent bystanders.
For concealed carry, unless you intend to wear a trench coat or carry a brief case, the pistol would be impossible to hide.
For hunting, it's out for me because semi-auto pistols and rifles are not legal for hunting in PA. If it is legal for hunting in Utah, it would be inferior to the AR-15 rifle in every respect. The only reason that anyone would use it over a rifle would be to increase the level of challenge for varmint or predator hunting. I wouldn't recommend this particular handgun for hunting big game of any species.
If you want to use it for home defense it would get the job done, but with a significant risk of overpenetration. I guess you could try out some of the special purpose defense rounds, but they are designed to perform at rifle velocities.
So if you want something to play around with on the range the pistol would be fine, but if you want a practical gun, the AR-15 rifle will be vastly superior.