The panworld pumps were designed by a former iwaki engineer from Japan. These pumps were initially imported by champion lighting as the "blueline HD" series, then also sold by premium aquatics, and I imagine others, as panworld pumps. There are very similar to the japanese iwakis, which is the MD line. They're ideal for big skimmers because they have excellent pressure curves. Just don't get the "high flow" or PXX models for a skimmer.

I've found that some models seem to be a bit quieter than the japanese iwakis, but overall they're very similar. Totally different league than MAG pumps, which IMO are glorified powerheads. 1000gph is not that big, and they seem to be rated conservatively. If you're going for a 1500 gph (maybe iwaki MD55 or equal panworld) and you're really concerned about power usage, you might consider installing a 240V line. I've seen several of the japanese iwakis that run off of 240V on ebay for a very reasonable price, and supposedly they're more power efficient at the higher voltage. An advantage to a 240 line is that if you use HQI ballasts with DE bulbs, they also supposedly work better and have lower power consumption with the higher voltage.