I started with a MEC 650, and would load once a year to meet my needs. The hardest problem was I'd had to learn how to use it over again every year. I upgraded to the Grabber model because I was using more than one shotgun, and some of my reloads would hiccup without sizing the head. Most recently (as I transitioned from competition rifle and pistol and into trap & skeet) I've upgraded to the MEC 9000H. I also have a Steelmaster for 12 ga, 3.5" shells, with the short kit to do 3" shells. The single stage presses are fine for the volume of hunting shells I load.
It is true that the progressives are best when set up for one shell and load, but with some practice the adjustments are not too difficult. Experience gives one a feel for the adjustments and the degree they need to be changed. For higher volume shooting like trap & skeet, nothing beats a progressive.
One thing I've done for all my MECs is to get the adjustable charge bar. Saves a bunch on individual charge bars and powder bushings, plus I can adjust for the volume differences between mangum and chilled shot, and for various powder lots.