I have two SDBs, as well as a Hornady L-N-L progressive. The SDBs are dedicated for 45 ACP and 9x19 each. I like the SDBs.
I prefer an auto indexing progressive, which the SDB is.
The SDB is great for one cartridge where nothing gets changed, in my opinion. The cartridge changes on the SDBs are not difficult, but require a bit more effort than other progressive presses to insure dies are adjusted correctly after changing.
The L-N-L is more versatile and lets me do a variety of tasks and methods on the press not easily accomplished on the SDB.
Cartridge changes on the SDB are not inexpensive. I decided I change cartridges by swapping out the entire press. Yes, that is more expensive than the bare bones change stuff, but it is fast, easy, and not adjusting to get things dialed in. (Dies, die mounts and powder measure is about 2/3 the cost of the entire press, if you do not buy the extra powder measure, cost goes down, about 1/3 the cost of the new press.)
I have a cartridge change kit for a third cartridge that i wish i had not purchased. I am not sure I will ever use it unless I find a used SDB or Dillon is willing to sell the press without dies and the powder measure.
I built a storage stand to store the unused press out of the way on a shelf.
Keep your single stage press. It is handy to have around.