I also am a long time emacs user, but whenever a plugin freezes emacs I immediately stop using it. Is is cider now stable? I know nrepl.el would crash emacs frequently if you asked it to evaluate the wrong thing.
I'm not sure how long this feature has been around, but C-c C-b will abort any running evaluation(s)... I've used it more than once to save a non-responsive cider repl session.
I've never had cider or the old nrepl.el crash or freeze on me, they've always worked fine. I develop on Mac OSX and Linux, what platform are you on? And what Emacs version? I tend to be on the latest GNU releases. Are you using a GNU Emacs or something else? If you're on Mac, I highly recommend this distribution [1]
I use Emacs on Windows too, but I don't develop there, it's mostly a glorified notepad for initial analysis of log files, so I can't really help there. I would recommend getting melpa setup on your emacs and keep cider as up-to-date as possible to see if that helps, assuming you're not doing that already either via melpa or directly from source.
For emacs/clojure users I highly recommend Sam Aaron's Emacs Live. It is an "opinionated" emacs setup and while some of the opinions might not be to your liking, it is really easy to set up and get going with clojure using it.