I don't know where they stand now, but back when I bought mine there was some discrepancy in the literature that prompted an e-mail to Streamlight asking 'bout the light output of the strobe vs non-strobe version. I was told by Streamlight that the strobe version put out more light than the non-strobe version (if that matters to ya), but after receiving it, I can't tell any difference.
I then thought maybe he was talking 'bout the strobe mode putting out more light (I was talking 'bout the constant light when I asked), but I can't really see why it would be designed in such a way? I think he was just yanking my chain to get me to spend the extra money.
Don't know that I'd ever use it, but I do like the fact that it's pretty difficult to accidently activate.
BTW-I was going to get another Streamlight Super Tac X, but see they now have the Pro Tac HL, so I opted for that instead.
That is one more bright light - darn near as powerful as the Super Tac's spot beam, but with tons more peripheral light, and no apparent dark rings, circles, etc.