Depends on how much ambient light there is.
I just got a TK11 and took it out to the in-law's cabin the last couple days. They have a clearing and a permanent deer stand that is 168 yards away according to a fairly old rangefinder. The TK11 easily illuminates at that distance. I didn't try it, but I have every confidence I could tell the difference between my father in law and one of his brothers at that distance with that light and obviously the TK41 will throw further.
I used to use an incandescent Streamlight TL-3 with two 17500s as my 'smaller throw light' and the TK11 beats it in every respect. Brighter, throws further, more reliable, longer running, more useful because of the two settings.
I was pretty up to date as of about 2007, but I've only bought two lights since then... an LD01 and now the TK11. LOTS of progress since 2007. Even compared to modded single LED lights that were pushing the envelope at the time.
I know lights with a lot of throw are impressive and cool to play with but honestly... if the TK41 isn't cutting it for you, you probably need to move to something considerably bigger. That would be my guess anyway. I've never used the TK60 or TK80, but the 41 is pretty damn impressive.
Edit: Oops... I misread your post. I've never played with the TK40, only the 41.
As to Fenix's claim... it's hard to say. The TK11 easily gets to 168 yards and they claim over 200 meters. I'd say based on the TK11, their claims are in the honest to slightly high range. I'll try to test it at 200 meters next time I'm down that way. I have no doubt it'll get there, just not sure how much 'oomph' it will have at that distance.