I don't know about filtration or which one is better. I've read also that cartridge filters are better than sand filters for filtration, but I assume that is all about regular brand "quality" equipment.
I do know that with the pollen falling in the pool, my filter is a slimey mess and I can't get it cleaned right now. I need to get to the store and pick up a few.
As for circulation, my 2650 or 2500 whatever it is cartridge pump circulates very well. I have a thermometer tied to the side across from the water inlet and it hangs out at greater than a 45° angle from the water circulating.
Cleaning up sediment from over winter (no cover) has been a real pain as I have to not only pull the little sock from the stock Intex vacuum out to clean every 1/16th of the pool floor I cleaned, but had to drain the pump and pull the filter and clean as well. It took me a week to get the floor clean and it still isn't perfect as half would pull up into the filter and half would get stirred back up into the water only to settle over night and would have to do it again every day for a week.
Large particles and pine needles and such are all finally out, but I still have sediment on the bottom that looks quite fine. I don't think the Intex cartridge filter is getting this stuff.
My plan is to upgrade to a sand filter, but first in order is I'm going on vacation in 3 weeks, so money is tight from that.