Vinh measured the MTS18vn (with low resistance mods) with brightest 6500K SST20's at 14,000L. Warmer versions will not be as bright but it's interesting to note that Fireflies lists both the CW and NW as 10,000L, which tells me that they're probably not being very precise. W2 versions of the MTS18vn would likely be in the 15,000-15,500 territory based on the fact that Vinh measured the XPL HI at 16,000L in the MTS18vn.
Indeed, the W2 ROT66vn Gen2 will be brighter than the SST20 6500K and if FF is calling it 10,000L it's probably closer to 8500L while the W2 is 9000+. Sometimes Vinh's lumen figures seem a little bit conservative when compared to others' measurements but even if you add 5-7% to Vinh's figures, it's all relative.
EDIT:
I just wanted to add that I think the Gen2 version is really neat. I like the idea of the added mass and I really like the small head size of this model. It certainly will have advantages in the area of heat sinking, longer run times and ergonomics when compared to a D18. It's all a trade-off and giving up some lumens for a much smaller, cooler running light, with aux LED's, might be the perfect compromise for some.