The efficiency is interesting, because there seems to be a pretty narrow sweet spot where this outperforms other options. Assuming you compare good bins at the same CRI, an LH351D is more efficient below about 800 lumens. Above 1300 lumens, an XHP70 is more efficient, and based on zak.wilson’s experience can probably also take more abuse. Now, both of those would lose efficiency if you dedomed them to get similar tint shift, but they’d also decrease Duv at the same time, which would require a filter on the MHD-E… So I suspect it’s a wash.
I think I’m going to end up using them at just around 1,000 lumens, even in a big chunky host like the L6. Basically keep things efficient and aim for high sustainable output, rather than the monster turbo power most people would use an XHP70 for.
For anyone who’s interested, these came from Arrow. They’re certainly cheaper than XHP70.