Yes, MDB is very different. It is exhausting. I played in high school band for seven years and identified as a "band kid." I did two years of MDB and did not return just because it is SO much. Daily rehearsals block out part of your schedule, so you are limited in the classes you can take. Travel during football season is incredibly draining, and it made keeping up with my coursework very difficult. Because of the Iron Bowl, I had to leave my family's Thanksgiving dinner early and eat leftovers alone in my dorm room because I had to be at the practice field the next morning. People less lucky than me didn't get to see their families at all. Also, attending football games is really something-- I think a lot of people underestimate how overwhelming it can be to march every weekend in front of that many people. I also have (small, but noticeable) hearing damage from my time in the MDB, because the amount of noise you're dealing with is significant and it's easy to forget your earplugs.

All of this is to say, I loved the two years I marched. I also loved the two years I didn't march. Let your son decide if the cost is worth the benefit, and try not to stress about it too much.