Yes, again the two applications are completely different beasts. There's no concept at all of scratch disks that I am aware of in Capture One. I also wouldn't advocate Capture One as a replacement for Photoshop and that to do a true evaluation, it should probably be set up based on phase one recommendations to get the best performance out of it such as making sure that hardware acceleration is on and working, etc. Personally, I find it extremely fast, at least as fast (usually faster) than Light Room, for example. LR is probably the application to compare C1 to. I've used it on everything from 12MP to 100MP files.
All that said, it's really down to personal preference. If you've been in Photoshop-land for years, the two systems are different ways of working with images, with pluses and minuses and making a switch may or may not be worth the brain damage. They're both great software applications that have a lot of users who love them. I personally use them both. It's hard to say what with your configuration is causing your issues and may be worth reaching out to phase one directly if you find doing something like that worth your time.