I am not a happy camper with them.
I am retired military, and still keep my M4 up to date. I bought the Surefire M73 based upon my personal experience with Surefire and my MP-5 Surefire light. It was wrong of me to assume the quality would be the same.
First off, I did read several reviews of the Surefire M73 where people complained of excess "flash" material in the rail grooves. I dismissed these as not relevant and more related to surface finish then functionality. I was wrong.
I bought my rail from Trader World Gun and Pistol Range in Charleston SC. I drove 110 miles each way just to pick it up. When I got home I mounted the unit on my Colt M4. Fit fine. Looked good. then I tried to slide my GG&G tactical foregrip on the unit....it became stuck on the unit about a third of the way down. Trader World did NOT want to deal with the issue pushing me towards Surefire. Surefire did not want to refund my money since I bought it from a dealer and not from Surefire directly.
Long story short I contacted Surefire speaking to George K there. Returned the unit and they confirmed that the rails were out of spec. GG&G makes to spec product....the Surefire rail was too tight on tolerances, and was actually out of spec due to the finish thickness. Surefire replaced the rail....but then the troubles get worse.
We then mounted the 2nd set. Everything locks up fine. Tried to install the GG&G, Fobus, slide on picatinny rail accessories....NOT a one would slide on the rail. The GG&G grip cracked due to becoming stuck on the rail.
Right now the rail is at GG&G being inspected. When I called Surefire again, their attitude was one of No way......can't be our problem. I offered to send the rail accessories we use on the first return to which they replied no. GG&G is doing a complete measurement workup, and is going to replace the grip. Their attitude is MUCH better than SUREFIRE's. I am going to send the entire packet including the precision measurements from GG&G to Surefire. Oh by the way...the grip measures to spec.
Surefire has problems with finish thicknesses. If you have a good one....excellent. But if you use sliding rail accessories such as GG&G grips...check to make sure they work.
B Wood