Flow rate!!!! this is the most important thing about pumps. There is a big difference between the eheim 1260 at ~ 640 gph and a mag drive 18 at nearly 1600 gph at 0' . huge differnece in electricity consumption. what is the size of the tank?
I have to clear about 68" of height, the flow rate reduces the higher you need to clear, Additionally I keep a stop valve closed to give alittle back pressure on the pump as I was told it helps with its effeciency and longevity.
Mag 18 is about 1350 GPH at 48". Hows the nosie on a Mag 18? I've read they are a noisier pump. As I said earlier this will be in my TV room. Quiet one 6000 is 1200 GPH at 48" and about $40 cheaper.