I really like the color of the Venture 55Ks, although they lack in intensity, as far as PAR. I had three 175s over a 75 and they worked great for everything, including a large T.squamosa. Over the summer I replaced the middle 55k with a 250 65K, green in color, but still not bad, although I much prefer the color of the 55ks, In a few days I will will replace all my lights with 2 400 watt 65ks, not sure what those bulbs will look like. I also have a 55 that I run two 175 ushio 10Ks on and I love them, they are bright, as far as PAR, and the color if fantastic, the bulbs are little more expesive than the lower K bulbs, but well worth the extra IMO. Depending on how the 400 watt Iwasakis turn out I may look into ushio 10ks for my 75 as well. HTH