Here is a brand new M250R2 that I ordered from Graybar. It is 150 watt HPS and has a plastic lens. It gets pretty hot. I'm surprised they actually make these in 150 watt with a plastic lens.
Nice! Fresh off the assembly line eh? I've seen 250W HPS lights with these GE plastic lenses and surprisingly they don't yellow. I prefer glass in general but there seems to be more of a variety of plastic lensed then glass. i've never seen a 150W light here. only 50, 100, 250, and 400 for new installations.