I've had them on a couple of my Glocks (including my main CCW piece) for a few years. Been through classes (both range and FOF) with them, etc. I like them and I think that many shooters, particularly those with poor vision, could benefit from them.
That said, I'm looking at trying something new, not because I feel handicapped by the Big Dots, but just to re-evaluate my choices since it's been a few years since I've consistently shot with anything else.