I just sold a 5.5-22x50 NXS and bought a 5-25x56 Atacr. I'm not a optics expert but here's my thoughts.
The Atacr brings out colors better
The Atrac resolution is pretty close to the NXS
The Atrac is brighter
The Atrac tunnels from 5 to 7 power, it should be called a 7-25 in my opinion
I wish...