Personally, I don't like it. I rate it below irons in utility. Some do though so it is worth checking out yourself.
Here are the issues I had with the Reflex:
Shooting from dark to light areas, the tritium/fiber optic doesn't illuminate the reticle enough and the reticle washes out
Shooting against bright tan/brown background (i.e. most of N. Texas) the amber reticle is difficult to pick up or disappears completely.
Both of the above can be corrected to some degree by adjusting the polarizing filter; but this gives everything a dark blue tint that makes it difficult to even acquire targets past certain distances or in low light.
There are better red dot sights out there than the Reflex.