I have both; an ATACR 5-25 F1 MOAR & a Razor 4.5-27 ebr2c mrad.
I feel the Razor is strong in certain areas: reticle design, fov, turrets, mag range and illumination control. The ATACR is strong with reasonable weight and rotating ocular for mag adjustment. The features of the razor are very nice and I feel a significant improvement over the ATACR F1. Clarity and overall optical performance is nearly identical and, in my opinion, couldn't be used to differentiate between the two.
Weaknesses of each: Razor is weight and I don't particularly care for the clickless zero. ATACR weakness: reticle options, capped windage compared to exposed locking turrets, terrible illumination control, very limited fov.
Both are excellent optics and I don't think either will disappoint.