Depends what light you’re working with and what orientation you want for your light. I have two with X300s (both ultra and original versions) and they have held up well. One had to be sent back to Surefire for replacing the end plate, but with 5.56/.223 they are solid.
I also have a Surefire G2 in Haley Thorntail and Surefire M600DF with Arisaka offset mount. All have been through carbine courses and still going strong. Two have been through no/low light courses.
The X300s and Streamlight TLRs get talked down upon as not being able to withstand recoil, but my X300s on ARs and pistols have held up fine.TLR one rifles and pistols fine as well. I mean I get “solid as a rock” performance and value tried and tested stuff. But I also go by what I’ve tried and tested. And I haven’t been “in the weeds” with this stuff, but have lots of buddies who have.