Fish,
Here is a quick story for you...
When I built the pool at my house, I really, really wanted a DE filter, because that is all I had ever used. But, the City requires that any DE filter be connected to the sewer, which would have been almost impossible.. So, I was "forced" to go with a large Cartridge filter...
Now, 10 years later, my view point is very different. I will never, ever go back to a DE filter...

I also have two rent house pools that still have DE filters and I can hardly wait for them to die so that they can be replaced with large cartridge filters.
Cartridge filters are dirt simple.. No multiport valve to go bad, leak or won't turn. Very low back pressure. I clean mine once or twice a year and my pool is open year round. In your location cleaning once a year would be plenty..
Can you replace the filter yourself?? No way for me to know. How handy are you?
In my mind, the perfect pool would have a large VS pump, a SWCG, and a large cartridge filter.. You already have two out of the three..
I have the CCP-520.. I would not get less than the CCP-420.
Or this one...
Thanks
Jim R.