I don't have a pr156. I have one of the 100w spots by them and two of the p38 bulbs and the moonlight. Re: pricing....I got the 100w spot during the "summer sale", so it was pretty reasonably priced vs say an ecoxotic cannon. The par bulbs I all got used, so they were also reasonable vs the competition. The pricing is WAY out of line. The par38 are very nice vs the other bulbs I have (nano tuners, ecoxotic, no name, wingoled) and have the most output (also draw most wattage). The moonlight is frankly the coolest moonlight I've ever used....that being said it is NOT worth the retail price. Retail pricing is ludicrous. I would say that they sold me the dif 100 as a 60 deg and it "looks" like a 60 deg lens. The stuff has only been over the tank for a month or so and I've been doing a lot of "other" fiddling with the tank, but the corals (mixed softie, lps the odd sps frag) seem to "like" the light. Lots of polyp extension, "fleshy" healthy look to things. We will see. I don't have complaints about the "look". Too soon to comment on longevity. But the pricing is just ridiculous at retail.