Received my 3x LH351D today. Installed them inside a Wuben TO46R. They’re really nice. No tint shift to speak of in the clear triple optics. A simple filter will perfect the tint on most modes if you need to be on the BBL. On higher currents it’s already superb.
And what’s amazing. It offers Nichia like beam quality but reaches output comparable to the XP-G3. I measured equal lumens before and after the swap. Although one of the original XP-G3s was dedomed so didn’t probably live to its true potential.
They are XP-L sized. I think they should be compared to the XP-L2 90CRI 4000K 2-Step, which is very efficient, but has a terrible tint (Duv 0.6 in the low/mid modes with reflector - SC64c). So this LED is indeed much better, similar to the Nichia 219C 4000K R9050 (which has a somewhat yellow tint though). At high currents it is probably noticeably brighter than the 219C R9050.
EDIT: I just checked the datasheet. At 3A the Vf is only 3.28V and the thermal resistance is 2.2°C/W. So it’s actually quite compareable to other XP-L sized LEDs. 765-810lm @3A & 85°C. 77-82lm/W, so definitely worse than the XP-L2 in that regard, but only because of the used Bin.
EDIT2: I just compared these measurements to those of the Nichia 219C 4000K R9050 403. The Samsung LED has a higher TM-30-15 Rf & Rg, a higher R9-value and a more balanced spectrum. The Duv ist very similar (unfortunately…).