Well, I received my Athlon Cronus BTR today and looks like I got a lemon. The illumination of the reticle is bad. It's off center and looks like it's being projected on another plane. I will call Athlon tomorrow and hopefully it will be an easy replacement. What I can comment about in comparison to my Tango 6, is that although the turrets don't lock, they have a better click and feel than the Gen1 Tango 6. The reticle on the Sig is thicker than the Athlon but the illumination is outstanding. I can't comment on the glass comparison yet since the issue with the Athlon made a not so happy camper.
I'll update whenever I get resolution from Athlon.
I'll update whenever I get resolution from Athlon.