Yeah, a lot depends on what sorta grip you plan to use. Vertical foregrips don't leave much room on the bottom rail for most light options, so you might bag your hand on the light, and they force you to break your grip completely for most side mounted lights. The angled foregrip leaves no room on the bottom rail, but still makes it awkward to operate some sling loop mounted lights, and you have to break you grip for anything mounted on the top rail. The factory grip gets your hand up higher, and allows for your hand to operate a light with a thumb or a forefinger for most side mounted lights. Lights mounted on the top rail would work well with a remote switch to the pistol grip, but the extension wire is a snag point and a failure point. The extended bottom rail might give enough real estate for a TLR-1 with a VFG to fit comfortably, but I haven't tried that... just food for thought.