I started with a Pan World 150PS, but switched it to a Dart on my AGA 120g using the AGA Mega Flow kits in both overflows. I made the switch because the Pan World was an energy hog at 180w. The Pan World was rated at 1,100GPH, while the Dart is rated at 3,600GPH.
You would think that since the Dart is rated at a much higher GPH, that I would be getting much better flow with that pump. However, since the Pan World is a pressure rated pump, it handles head much better than the Dart. I believe I was getting around 1,000GPH with the Pan Word, and I'm probably getting 1,100GPH with Dart. The nice thing is that I have now increased my flow slightly and reduced my wattage by roughly 45w.
I also use a Dart on my closed loop.