It's a fine sight, but I've found it not bright enough for outdoors, and too didn't care for the relatively low battery life, or the on/off switch. The adjustments were harder to get right, and seem fragile. I too have heard
problem with them holding zero, largerly due to the fragile locking screws on the adjustment screws.
Also the housing didn't seem as durable as that of a Docter.
A Docter being my recommendation if you can front the extra money.
For a plinkers I'm sure it's just fine, but if you storm is for home defense, then perhaps consider the Docter.
A picture of it on my XD and Docter is here, which is only a plinker too, but I learned it doesn't really save to go cheap.
XD9 w/ Trident 9 and Docter RedDot
Only buy from this site-> Home
not only the cheapest, but you get the latest gen, and too a US factory warranty, opposed to a German.