Excellent magnifier. - Sig Sauer 4x 24mm Juliet Red Dot Sights Magnifier

I'll be comparing it to the Holosun HM3X I owned first.

The Sig is sufficient for dealing with my astigmatism, about on par with the Holosun, which is odd given the fact that this only has a +-2 diopter, whereas the Holosun has a +-3.

Clearly a peg up in quality all around- yet not THAT far off. The mount, however, is a definite step above in terms of just how durable the actuation of the flip to side feature seems to be in comparison, and how solidly it locks into the rail.

The Holosun's got this beat in field of view, but takes up quite a bit more room on the rail (mucking with things if you want to keep your BUIS with certain optics, like the 510C) and is, obviously, a 3x. It also has a bit more eye relief and a bit wider eye box, which is to be expected given the bumped up magnification on the Sig.

Glass clarity is great. No complaints about the finish on my FDE variant either. And the included glass protectors are a thoughtful addition.

All in all? You'd do fine with the Holosun. It's really up to you if the stuff I've mentioned is worth the additional cost.