I have 2 of the BURRIS XTR-II 8-40 and here's the reason why.
I'm an ex TR shooter and was always taught about the importance of the sight picture, "the target does not have to be a perfectly crisp all the time but you need to see something so you frame it". This is what led me to F-class, I couldn't see the blob at the other end anymore. I now shoot F-open.
I started shooting F-TR in 2016, thus converting a Phil Mastin's Nelson 600 TR rifle and bolted a NF Comp on top. I won the NQRA F-TR Queens with it but, I was not completely satisfied with the sight picture. While I could see the target at the other end jumping around the dance floor, in mod to heavy mirage, the thin recital would disappear every other time. Being new to F-class and scopes, I didn't know any better; until Dave Mac showed me the Burris.
After the first time out with the Burris, shooting in the mirage in Cairns, I was hooked. My younger years of TR came flooding back; I could see the sight/reticle clearly all the time because of the thicker lines. The other pros and cons are:
[*] The reticle's are MOA and their setout lines up with the rings on the target regardless of the focal power due the the First focal plane.
[*] You can centre the retical dot/circle in the X ring.
[*] When the mirage builds and the X ring disappears, my eye automatically tracks to framing the 6 ring and so on and so forth.
[*] Couldn't see any different between the NF Comp glass and the Burris glass but that could be my eyes.
[*] The 1/8 clicks are solid.
[*] Zero stop is easier to set up than the NF Comp
[*] I find the First focal plane compensates for the lack of the extra 10x because its a great framing scope.
[*] Its heaver than the NF Comp - not a problem in F-open
[*] The reticle can be busy to some people.
[*] If you don't like to 'frame' and only like to put the cross hairs in the middle, maybe this is not the reticle for you.
[*] While i have no issues with the Burris at 900m and have shot 60's with it at the same distance, 50x power would be nice.
My theory is, find a scope that best suits your eyes and sighting picture to suit your shooting discipline. I have and it happens to be a Burris XTR-II 8-40 x 56. I purchased a 2nd as a back up.