Few topics in pooldom engender more rancor than the seemingly innocuous filter. Its almost as bad as politics and religion and each type, cartridge, diatomaceous earth (DE) , and sand, has developed cult-like followings. In my research I found the following general consensus (though by no means unanimous) opinions on filter types:
DE = Cleanest water, between sand and cartridge for maintenance and life cycle costs;
Sand = Easiest maintenance, cheapest over its life cycle, third of three for filtering (but still good);
Cartridge = Most maintenance (but still pretty darn easy), most expensive over time, between sand and DE for filtering.
All three types have their advocates and detractors (though cartridges seem to have the fewest advocates and the most detractors).
For the record, I have a a sand filter filled with zeobrite. The filtering with this setup is supposed to be rival DE but provide the ease of maintenance of a sand filter. As is usual, the zeo peddlers overstate their case; it's a good setup but DE it ain't (and probably not even any better than a cartridge).
No matter which type you choose, over sizing the filter is almost universally acknowledged as sound practice.