I have both surefires and stream lights I use on my work guns. I much prefer the stream light TLR1-HLs they’re a bit shorther than the X300 Ultras, but the switch mechanism is favorable also which is the big reason I like them more, both are fantastic and throw light not only much further than you will be able to shoot accurately but enough to comfortably see anything that goes bump.
I moved my 2 300 ultras onto rifles and the three Glocks I regularly carry 19,34 and 17 all have TLR 1 HLs on them. I have some smaller lights also but still use the TLR 1 HL on my 19 which I now typically carry concealed in plain clothes both at work and off duty because I’m a firm believer in always carrying a light on a pistol.