I have several IOR scopes. The M2, 2.5-10, and the TGA spotting scope. My 2.5-10 is SUPER clear and tracks great: VERY REPEATRABLE. The overall fit and finish seems to be lacking though. For example, on the elevation and windage turrets have no indicator as to which is up, down, left, or right. Granted this is not a big deal...but it is a nuisance.
I recently purchased a 4-14x50 with the second plane reticle and side focus knob (this is the "new style"). The scope had SERIOUS problems. First, the eyepiece was loose. Secondly, the power ring seemed to "grind the" lens when changing power AND the rubber ring around the diopter adjustment was loose or too big. Thirdly, the reticle would not come into focus (which may very well be associated with the other eyepiece issues). I spoke with the IOR importer and sent the scope back for warranty. After two weeks I received a NEW scope (literally BRAND NEW can't complain about that). But it gets worse. The second scope had the same issue with the rubber piece being too big on the diopter PLUS the rubber piece on the power ring was too big. Frustrating but again no big deal. I mounted the scope on my 700PSS with a 20 MOA tapered base and headed to the range to zero it in. I finally got it zeroed, but much to my dismay I only had 6 MOA of upward elevation adjustment WITH a 100 yard zero. Had I been using a standard flat base, I would not have been able to zero it at all. I think the product is a good value but the quality control is lacking. Leupold has upgraded their optics and I'm thinking of trying on of those.