I bought it some time ago and have probably used it in every project.
Like Keni, I love it on bass. I also use it a lot on vocals.
As Oleman mentioned, it can be useful to put it after a fast compressor, like the PC-76. This can catch the peaks. I use that combination on almost all of my vocal tracks.
Don't forget to play with the screw. The way it changes how the CA-2A compresses higher frequencies is great.
I love this comp.