One of my coworners turned me onto CopyClip a few weeks ago, and I instantly fell in love with it. Having a cache of everything I’ve copied is a feature that I’m surprised isn’t a part of the OS already. That being said, I haven’t experienced any sort of lag after I’ve started using the App (atleast none that I can attribute to CopyClip), and I’ve got a macbook air with 2GB of RAM, so it would be pretty noticable.
The only complaint I had was that when my menu bar is in dark mode (ie. all the time) I couldn’t find the icon. That being said, after a quick email to their support, they quickly instructed me on how to change that icon so that I can find the icon. I’m very impressed with these guys, mostly because other developers that I get in contact with over similar problems just say that I’m out of luck. Again to restate, Flip Lab, has earned an almost lifetime customer out of me.