I like these switches alot. I've bought other keyboarda and switches lately and i end up going back to my k4 with LK optical switches again... It's quite sad that newer keyboards don't offer them anymore.
I ordered these to replace the blues that came with my K4. At first I thought I would like the clicky sounds but eventually, it drove me nuts. I installed the reds and was not disappointed, after lubing them, they were even better. The only wish I have is the need for more options in that style of switches.