Detecting a form change. Is jQuery the way to go?
Will using jQuery to attach a change event on each checkbox take a major performance-hit?


Probably, but it depends on the client's configuration. I have a form with around 3 hundred of controls, half of them hidden, some of them auto-copying content using jQuery, and sometimes FireFox has it's problems with it.


  Is there a faster Drupal way to do it?


Nope, Drupal way is to use Behaviors, or states, and Behaviors &amp; states thou shalt use... but they are merely Drupal's way to initiate jQuery-based code.


  Will using the Drupal way, make performance faster?


Nope, as Drupal way is basically jQuery way too. But it will merely allow you to be reasonably sure that other modules will not interfere with your code (without any significant slowdown).