The AR-platform has been called "Legos for grownups," and for good reason. The average person capable of replacing the batteries in a smoke detector can swap out a large number of parts without undo distress. If you're capable of following instructions and field-stripping most firearms, you can change out a good number of parts without issue.
One such part is the pistol grip. With most grips, all that is required to change the grip out is, literally, to unscrew the old grip and screw in the new one. There's not a lot of special equipment needed, although you do have to remember to capture the safety-selector detent spring before removing the old grip and put it back when installing the new grip (not like any of us have ever forgotten, then wondered why the safety selector wasn't working right, nossiree...)
TangoDown's Battlegrip model BG-16 has been designed to improve on the standard AR-15-style grip. Its textured side surfaces ensure solid purchase, while the rakish angle—almost Luger-esque—assists with pointing and ergonomics. The construction is solid, and the internal compartment designed to hold standard CR123-size batteries is weather-resistant.
Little touches help an upgraded part stand out, especially in a mature field like replacement grips. The Battlegrips are well-made, with smooth edges, aggressive texture and fine ergonomics.