Well it largely depends on where you live.
I'm in Illinois and our house is right next to a Forest Preserve. Our pool is surrounded by Oak Trees. Thus, we get ALOT of organic material in the pool and we are constantly fighting algae
We have skimmers and things, but alot of it goes into the filter. DE filter very tiny particles. Our clogged contantly and the pressure would get very high. I would have to open it up, clean it out, drain out all the old DE and replace it several times every summer.
The cartridges work much better for us because they don't clog as easily. Plus, I have an extra set. When I remove one set I set them to soak in the cleaning solution and then rinse them off. I only need to change them a couple of times a summer. I just open it up, stick the clean ones in, and close it again. It is much less messy and doesn't take nearly as long.
People who live in "cleaner" areas than our pool don't have near as many problems with the DE filters.