Oh, it varies. I thought I had a preference a long time ago, but it turned out to be borne of ignorance. Most of my sharpening was freehand until I got into modern steels, had to get better stones, and educated. Thanks, fellow knife nerds on the internet. I still like to freehand my D2's, 1095's and 420's on old stones, but I like to try and keep the angles more consistent and not just erode the metal.
My modern steels, unless something chips or rolls, I'm only stropping. Mostly. Right now the only diamond I have is a rod, but it can be fixed to match angles. I don't aim to reprofile if I don't gotta. And if I do gotta, I'll see if the manufacturer will fix it first. For instance, I got a Buck Onset that I do like, still factory sharp enough for me, but the edge looks like each side was ground by a different bladesmith on different days. On different machines. In different factories. When it eventually needs touched up, I reckon it won't hurt to call and see if I can get just one person to service it before lunch.