I need two. Both seem to be recommended. Both have 4-5 stars. I've had both. I'll install both of them and date them. Have my own little test. The website said the both draw about the same amount of power, so they probably are pretty close on heat.
The bad thing is what it has done to my tank. The corals, as few as there were are having a hard time.. dang. I guess it disolved some of the copper wire and rubber. I'm changing more water tomorrow. One of the pumps was a Dolphin and it was probably only a year old. The impellar was all swollen up and it would kind of spin, but it was hit or miss. The other was a Rio.. What do I expect....