Very cool! as far as I can see, the TIR lens has not changed since the time they changed those small lenses for XR-E to new ones that are still in X300 and modern E2D 1000 lm. The densest beam that I saw in this TIR was on EB1 with 200 lm and inside XP-E. Does it turn out to be even denser or about the same, but brighter?
I have one other similar light, the EB1 although it was the 300 lumen model (XPG2), I've also modded it. I put a 219C in it that one and a 2.3A driver.
I've never seen the EB1 with the XPE in stock but I have modded one (300 lumen model) to XPE2 but that was a while ago.
I don't currently have any figures but the XP-P creates a more intense beam than my 219C/2.3A light and would likely very easily out do the EB1 200 lumen model.
Compared to the original E1D LED 300 lumens, the XP-P would definitely be brighter, hotspot tighter and throw considerably further.
Sorry I can't give anything in the way of reasonable comparison or figures, but I can safely say that just going from the stock XPG2 to XPP is as big of a difference as you'd expect and the TIR plays well with the swap.
EDIT:
I added a light meter app to my phone and used a paper diffuser to get some measurements, take these for what they are.
All measurements taken at about 1 meter.
EB1 modded with 219C/2.3A driver: ~10Kcd
E1D modded with XP-P/stock driver: ~20Kcd
Convoy C8+ with XPL Hi/H17Fx: ~85Kcd
(EB1 head used on 2 cell body, 16650. E1D on single cell body, 16340).
This isn't the most scientific but should give an idea.
For Surefire to get 71Kcd out of the new head the reflector must be great and must be pushing some serious amps out of a small cell (EDC1), can't imagine it holding it for long.