I had a G&P ACOG 4x, clear glass and solid as a rock. I've dropped it a few times and it's perfectly fine. As for holding recoil, it was on my WE M4 and the thing couldn't shoot as straight as an AEG so I took it off. For the few hundred rounds it was on the GBBR though it held its zero.
On the other hand, the reticle was off by about a degree or so making it canted to the left. It's so slight I didn't actually notice at first and then I assumed it was my mount that was off. I doubt they're all like that, I've got other G&P sights and they're fine for clones so I'm guessing I had a lemon.
Eye relief was OK, I can't remember how far your eye had to be but I do remember positioning the sight so it was as far back as possible.
Last edited by GSK88; July 19th, 2011 at 12:49..
Reason: Added info