I'm not a Magpul fanboy and I was never a fan of their original gizmo. But they do produce thoughtful, well designed, useful gear. Their mags are great. Their grips are excellent. I'm seriously considering replacing my Ergo grip, which I've had for years and love, with a Magpul MOE grip.
I think Magpul became successful by not resting on their laurels and relentlessly manufacturing good gear that people want to buy.