This is kinda not a bug in El Capitan itself but yeah, it impresses me that Logitech Control Center stops working at every new release of OS X.
With Mavericks and Yosemite i could not even open LCC, with El Capitan i can open LCC but none of my Logitech devices have the common decency to pair with my computers.
Agreed. My impression from having this happen over and over with Logitech is that their attitude is, "We don't have time to deal with pre-release/beta software. We'll just wait until its final, piss off a few customers, and then they'll be thankful when we finally release a working version."