I had a new P1D CE that I used for several weeks. Then I got a T10 for my brother, but he liked the Fenix better so we swapped.
As far as I can tell, the Olight is comparable to the Fenix in every way. I actually like it better for two reasons: the low setting is 7 lumens v. 12 for the Fenix, and it remembers the last setting, whereas the P1D reverts. I can see advantages to both, I just like the memory better because I use the light on low a lot to preserve some night vision.
Downside: I liked the adjustment system better on the Fenix. The Olight is reversed, and less convenient in my opinion.
Note: the bloody bezel and reflector housing will get HOT if not exposed to plenty of air on level 1, but the output seems to hold up so I'd say the heat sinking is doing the job.
Either is an excellent choice. The operating system is more important than the manufacturer in this case, I believe.
For what it's worth, I've noticed some really rude and unwelcoming people on these boards. It's the major reason I don't hang around more. Grow up and join society, people.
ADDENDUM: I forgot to mention that the Fenix uses a power reduction system that produces some strobing at the low setting. It's not especially annoying, but it's there and could cause some issues if one were illuminating mechanical equipment, I suppose, or especially sensitive to that sort of thing. (It's not as annoying as a Photon.) The Olight does not strobe, and it's my understanding that they use a linear reduction system that reduces the voltage rather than switching the diode on and off.