I've always used the standard mil-spec charging handle. All that crap is cool factor stuff and does nothing to improve functionality. Left handers just toss your index finger over and pull with two fingers. It ain't that hard!
Reloading step 1, get behind cover.
Reloading step 2, press mag release and strip mag out and into dump pouch, grab fresh mag, insert into mag well, seat and tug, press bolt release and watch bolt strip round off the mag and feed into chamber, tab foward assist and close the ejection port cover.
You have now properly reloaded your M4, and no you do not need to make all kinda of robotic movements to make it seem like you are doing it better, like the MAGPUL clowns did.
Tactical Reload step 1, get behind cover.
Tactical reload step 2, take out partial mag and place into dump pouch, take out fresh mag insert into mag well and tug to ensure it locked in. Check to ensure bolt is foward and close the ejection port cover.
Emergency reload step 1, transition to pistol until behind cover.
Emergency reload step 2, see reload step 1.
It really ain't rocket doctor shit and is really just that simple. Need to improve reload times? Practice for 20 minutes a day, two to three times a week until its second nature.