I have the M1000 mounted on BAR 30-06. A friend has the M1200 on a Remington 700 .243 WSSM. They both perform very well and there is no problem with FOD in the mechanics. The ART type scope has been around since the VietNam war, where it made its debut and was used quite successfully in the jungle terrain, during monsoons, under extreme conditions. My M1000 has not had heavy usage, under 50 rounds since I installed it. I find the cam mount quite easy to adjust and operate.
I also had one of the older 3-9 Sporter models mounted on the BAR, generally 100 rounds per year. It was my primary hunting rifle/scope combination for many years. The initial adjustment, getting the scope tuned to your ammo, is nontrivial for some. However, once accomplished, there is no faster way to get "on target" out to the max range of the scope. Bracket a target area of known size (say 18" target area on a "normal white tail deer), put the crosshairs on the point of aim, shoot. I have not missed with either scope. With the Sporter, I once took two running deer within about two seconds of each other (then I had to carry them both up a 1200 foot rocky incline and about 1/4 mile through the woods to get them to the truck...wished I had not shot the second). I have unusually good luck with scopes that other people don't seem to, but I have no complaints after 10years with the Sporter and a year with the M1000. My friend has had the M1200 for over two years now and has made shots on beaver out to about 700yds with it. I mounted it and set it up for him, he just brackets the target and shoots. The glass in the M1200 is not as "good" as the glass in my M1000, which is a newer model. I believe the M1200 glass has been upgraded to the same quality as the M1000, but you might want to check with the company on that.
I am not recommending you purchase one, just giving you my real world experience with those three systems.