Ok, can you open one of the files that have been very very slow to save, then show me a screenshot? Of the entire Photoshop screen, including layers panel and everything.
It doesn't matter. What matters is to check that you're working on 8-bit files, not 16-bit files. 16-bit would definitely contribute to the problem you're describing.
The features are all still exactly the same. But yes, the buttons look different. I think you need the little icon immediately to the right of the "H:500px" in the options bar.
Ok. You mentioned that you'd tried the various white temp options in the Spyder software.
But are you sure you chose the best colour setting on the screen itself? What are the options called, and which one have you chosen?