I have a little experience with the Maya muscle system, but I think many people over complicate it or just feel intimidated by it... This is not to say that it's not difficult.

It is a little tricky at first but it doesn't take much to add basic muscles to your rig, you would of course have to mess around with it and tweak some things to get a basic understanding but once you do it isn't nearly as difficult as some might think and once you have a basic understanding of how to use the Maya muscle system it's not too hard to get into the more complex stuff... I would recommend a reasonable amount of knowledge regarding building rigs before jumping into that though.

One thing is for sure though, once you get into using the muscle system with your rigs for your animations. They will definitely look much better and stand out more, providing you do it right

I would say that it's definitely worth exploring the muscle system and seeing what you can do with what you learn.