Have an X300 and an X300 Ultra. Have not had an issue with them other than the X300's lens gets covered in powder much quicker than my X300U in my experience due to it being shorter. That and the fact that it is a bit of a pain in the ass to mount to a pic rail since it always seems to be rather tight and you can be limited to mounting options/position on rails where as the TLR series can be mounted without having to slide directly onto the rail. This can be important when you are running a rail on an AR with a FSB. Other than that I quite like them, quick and easy to mount to a pistol, the switch is a much better design, though I sometimes wish it was a little larger, and it locks up in my holster tighter than my TLR1 did. And this from someone who has owned three TLR weapon lights, a TLR1, TLR1s, and a TLR2s over the course of several years having few issues other than one not wanting to mount proper, after running the Surefire for a while I sold the Streamlights and have since gotten to wear all of my weaponlights are Surefire.
That said, for the money the TLR1s are hard to beat.
"I don't collect guns anymore, I stockpile weapons for ****ing war." Chuck P.
"Some days you eat the bacon, and other days the bacon eats you." SeriousStudent
"Don't complain when after killing scores of women and children in a mall, a group of well armed men who train to shoot people like you in the face show up to say hello." WillBrink
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