A few more details on why I like the offset sights and backup sights in general. When my Nightforce went down (they said it was a lens separation or something of that nature) I could no longer adjust parallax or get a clear image at any range or magnification. POI was also fouled up because of the parallax issue. Basically think of covering your scope objective lens with mineral oil and looking through it lol. In this case I simply removed the scope (THANKS ADM mount lol) and used some plain old magpul flip ups. Did the job just fine.
The US optics lr17 did something similar, and I expect they will tell me something along the same lines. Basically the scope was unsuitable for any kind of precision work at all. This one went down on a hunt. I had a backup rifle here, and simply switched.
The leupold scopes that failed all lost adjustment ability and lost zero during target shooting. Not anything exciting here, but backup irons would have kept me shooting without any fuss.
Most notable to me is that none of these scopes seemed to fail due to any explicit damage, ie I did not drop any down a mountain. I think they were mechanical defects that took time to manifest themselves fully, or just plain old wear and tear. Simply put, those things can happen without warning, rhyme, or reason.
I like the backup red dots as well, but there is a lot to be said for the simplicity and ruggedness associated with good irons.
As far as QD mounts, ADM and Larue are top notch. they return to zero well and are good quality. I prefer the clamp style on the ADM, but thats just personal preference. No issues with the larue ones here at all.