MSG is naturally in everything like cheese, tomatoes, mushroom, yeast, etc. You do not hear the "Chinese Restaurant Syndrome" from high end restaurants ever, because they use better ingredients, charges more ($20-30 per dish), and don't abuse them like the low end mom and pop places competing in prices use them for. It really is a sodium overdose as MSG doesn't taste salty like salt does and it is very easy to OD MSG.
I once heard of a ramen place in NYC that said "We absolutely uses MSG and we are proud of it". That place was always full of people and has good review.
Yesterday I got a MSG OD from the BOGO deal of McDonald's Sausage McMuffins. Can't taste anything for the whole afternoon despite 1 cup of black coffee and 1 cup of plain black tea afterward.
MSG got a bad rap from overuse. All it takes is a tiny amount. Adding it like salt is way too much.