Say I with a modded X60Mvn in hand, and high drain batteries. Modded this light is NOWHERE NEAR 10,000 lumens. Stock I expect it's around 7000 lumens at best.
I suspect that's also the reason we haven't seen a good review of the light either... they know it's underspec, but calling it a 10,000 lumen monster does help with the marketing.
My conservative measurements of stock X60M with high drain cells show about 8k lm, and my light tube is known to underestimate lumens of lights with wide beam => I'd say that a fair estimate is 9000+ lm.
The wide beam makes it look significantly dimmer, especially if compared to X60 side by side, but the total output is there.
..and a bonus photo to show the beam profiles.. (Note that X60 is slightly modded and equipped with 4D tint emitters)
(FWIW, I like X60 beam profile better - but there are uses for X60M's smooth & wide beam too, like photography..)