I've had cartridge filters in all my pools and wouldn't have it any other way. So, I'm not a de filter expert at all but I've observed friend's pools and in every case where they've called on me to help them fix their ailing pools, they've had poor circulation issues due to their de filters constantly slowing down the flow rate of the water. I'm helping my neighbor now get his pool in shape after a hard winter and his filter runs for a short while and the flow slows down to nothing. We used to clean our cartridges once at the end of the season (we clean them a couple times now but not because we have to, it's because we want to) and always have a really strong suction/rate of return. I say what good is it to clean down to 1 micron but you have lost a lot of the flow rate of the filtration . . my neighbor put his hand in our pool to feel the water blasting out of the returns compared to his little trickle and was convinced that cartridge is for him.
Best,
Jan