Once you get used to your new machine you will love it. I have run a 550 for decades. Simple and quick to switch calibers. No better tool to learn progressive methods.

I have owned both a 1050 and a 650 but they went away. The auto index, higher volume and case feeder couldn't justify the time spent on caliber changes, adjustments and the space the machines took up on my bench. If I had bench space for a loader I was going to set up for a single caliber i would have kept the 650.

I don't load rifle ammo on a progressive press and never load more than 1000 rounds at a time. For my primary calibers, 9mm and .357 I use all Dillon dies except for a 9mm Lee taper crimp die. (I use the Lee crimp die on all my auto loader ammo)

For other pistol calibers I use the same dies I used on single stage presses back in the 80s. (Mostly RCBS) The Dillon dies run smoother & faster but I'm in no hurry. Round count between the 2 types of dies doesn't vary more than 25 an hour or so. Taking my time I average between 350 and 400 rounds an hour.

I would like to get a second 550B just to avoid switching from large to small primers. Truth is swapping out the primer feeder isn't a big deal, but it is more complicated than the caliber switch.

Good luck.