Most effects and many instruments, whether Cakewalk's or third-party, can simply be copied over. Last time I got a new DAW, I kept the old computer on the network for easy copying.
I first copied over all my old projects and loaded them up into SONAR one by one, and whenever the missing-plugins dialog came up, I copied and pasted the list into a text file I named "MissingVSTs.txt". This identified any missing plugins that I'd actually used in the past. Any that I'd never used, I figured I didn't need to worry about.
Potential exceptions are virtual instruments, which may have a large number of files. Some have license files in addition to the main DLL. Even then, you can usually just copy the entire file tree. I can't think of anything from Cakewalk that required a re-installation, but even if you do they make it easy to re-download anything you've bought from them in the past.
OK, there was one exception. I could never get Dimension Pro to authorize. I uninstalled it, re-downloaded it, re-installed and applied the activation key given on the download page. Nothing worked, so Dim Pro just got retired.