If you are thinking of buying an overpowered pump and running it at a low rate to make it last longer, make sure you check the manufacturers instructions first as they may recommend a minimum rate.
I have an aquamedic return and I am really happy with it. I bought it thinking I’d run it at about 50% or less but once at home I read the manual which stated it be run at 65% minimum and so that’s what I run it at.
I did a bit of an analysis in another thread when I was deciding how powerful a return pump I needed. I’ll try to find it.
Also, I like having a larger pump now because when I am cleaning the display I’ll run the return up high to suck a lot of crap through the sumps filter sock.
Another thing I learnt was that the sump’s capacity is also a limitation. If the sumps small and if you don’t have a lot of water in the sump, when you run the return pump up high you can load the display tank with water and end up with too low a level in the sump and end up sucking air through the return pump.
Lots of little things you learn through trial and error.