Good overall, slight learning curve - ADE Advanced Optics RD3-006x 1x Reflex Green Dot Sight w/D1 Rear Optic Mount Plate

This was my first pistol optic, so finding the dot consistently took some practice. Once I got used to it, accuracy improved noticeably.

The optic itself works well and has held zero. Four stars only because I wish the brightness adjustment buttons were slightly larger.