I'm a high volume pistol shooter, so I think next year I will step up to a Dillon. I knew going into this that I would end up on a progressive, but I will still use the single stage for my rifle loads, and even some pistol loads that I don't shoot as much as my 9mm, .45acp loads.
If you haven't already started saving your brass for pistol loads, I suggest you start doing it now. You can't have too much brass on hand when you are loading pistol ammo on a progressive press. 5 gallon buckets of brass on hand is a good thing to have.
Many reloaders tend to have certain times of the year when they have more time to do their loading. High volume shooters will enjoy having a lot of ammo loaded and ready to shoot when there is less time to do some loading. It is also nice to have enough of everything on hand to get through times when ammo and components are in short supply. Even low volume shooter will see the advantages of having enough on hand to get through those times.