It's just slower and the ability to acquire a target and shoot while your hand is still in movement to the foregrip. Another issue is with malfunctions, to remove the mag and work the action, re-insert mag, get back to work. If you are using your right hand on a standard AR, you will be in a world of hurt to remove the mag, and work the action without fumbling around with the rifle. If your hand is away from the pistol grip, you can't work the safety. The beauty of the AR platform is how pretty much everything can be done with your hand on the pistol grip. The only time I use my right hand for anything is to lock the bolt back, which only happens during a complex malfunction, or to safe the weapon.Yeah, kind of easier for me. Probably a bad habit. I find racking with my left on a standard AR to be a little awkward. I know I should just train through it, but I have to urge to hold the rifle with my left on the foreend and rack with my right after taking it off the grip. The left side charger accommodates my questionable form* without any real downsides.
Edited to say: That last sentence didn't make sense. What I meant is that the side charger allows me to have correct form without feeling awkward.
It's also super tacti-cool.