User experience has been horrible for years now. I was convinced that my PC was too slow back a year ago. But now I have upgraded to 16GB of RAM, switched to a modern Quad Core CPU and bought a NVIDIA GeForce GTX1060 graphics card, and Photoshop runs like a breeze on my new PC. On the other hand, however, Lightroom remains to suffer from lag even after maxing-out every possible optimization options.
Heck, even adjusting curves in Lightroom is a total nightmare.
PLEASE. ADOBE. HAVE THIS GOD DAMN THING FIXED.