I've taken the Experienced Rider Course (ERC) twice. I'll probably take it again this year. It's not the perfect course, but for $50 (MN), it's well worth it. I will say this- some instructors are better than others, and that can make all the difference in the world.
Some rider's clubs (Honda Rider's Club of America) will pick up the tab for your class. Some insurance companies (not mine, of course) will also give a discount on your premium. In MN, they give you a list of businesses that will give MSF course graduates a discount.
If saving your life isn't enough, then do it to save some money!
I never took the Beginning Rider Course when I learned to ride 22 years ago. I wish I would have- it would have saved me a crash, and a lot of "pucker factor" experiences!
I'm currently on a BMW. It's amazing the percentage of BMW riders that have taken MSF or other courses. Apparently it's just a different mindset. Of course, if you're hanging out with your buddies, and you're the only one who hasn't taken the class... you'd feel like I did going to the IA Freedom rally, wearing my full face helmet!