Cool yeah im torn about going with sand but like the idea of the water being "cleaner" with the cartridge.
I add a small amount of de to my sand which helps with the finer particles & my pool stays crystal clear.
There’s many ways to skin this cat.
The main advantage of the cartridge filter is not dealing with the backwash water.
The disadvantage is that you must clean the filters manually at some point.
If you get an oversized filter (no matter which one) the cleaning/backwashing will be a somewhat rare occurrence if you keep your pool algae free. I have a 250# sand filter & 26k gal pool. I backwash approximately 3-4x’s a season which includes opening & closing. My season is 7 months long.
A large sand filter takes up more space than it’s comparable cartridge or de counter parts usually so that must also be considered.
Sand filters are easier/quicker to clean (backwash) & take a little longer to clog if you are dealing with algae. Hopefully with TFPC methods this will be a non issue.
They are also generally cheaper than their de or cartridge counterparts of comparable size. Most cartridge set ups don’t have a waste or recirculate option so if you want that you will need a separate multi port valve. Not sure what your set up is now (if your mpv is integrated with your filter or separate).
If money were no object I would probably go with the largest cartridge filter I could find & not have to clean it more than yearly nor have to deal with the backwash water loss & drainage.
There is no wrong answer other than ensuring the filter you choose is at least adequately sized.
You just need to determine which attributes are most important to you.