I've had a Porter Cable for about a decade and it's very good. It uses velcro disks. They are 5 hole and easy to source. It's variable speed. A couple of years ago the velcro base de-laminated but it was easy to get a replacement from the PC and install. The dust collection filter it quite good or you can hook it up to a shop vac.
I also have a Makita palm sander. I don't like it nearly as well. The sand paper needs to be cut from standard size sheets. Then punched for dust collection. It's single speed. And the dust collector filter is just so-so.
And while this has nothing to do with your question, I do lots of hand sanding. For the face/back, the kind of sanding you'd do with a ros, I use spray adhesive to tack sandpaper down to a large piece of mdf (usually 3 different grits) and slide the scrolled stock back and forth a few times on each grit.