I recently moved from two Radion Pro's G3 to the Geisseman Aurora hybrid which is a 4 bulb setup. I had great success SPS under the LED's but as they grew larger and larger there was a lot of shadowing that was eventually causing me problems with the coral bases. My Tank is 36 Inches long, 24 inches front to back and 30 inches tall. If there was an option for a 6 bulb model I would go for that first and if I had the chance to do it all over again and 6 bulbs were not an option I would go for the ATI 8 bulb hybrid. My overflow eats a large portion of the rear middle but the extra lighting would help me keep some corals such as Stags towards the rear corner walls. With that said I have noticed some differences since going Hybrid which is nice. The most obvious is more of a metalic glow on corals such as millepora (after about 7 weeks) and upward branching growth from areas where sps have encrusted which was unexpected but very nice to see.
