Another vote for leaving it out. It's not good for anyone, and those who are especially sensitive to it can have reactions so severe they end up in the ER.
A word to the wise--for those who want to avoid MSG. You need to educate yourself to the dozens of terms that manufacturers use to HIDE MSG in commercial foods. Years ago, I was unaware of this practice. Ate some commercially prepared food that--according to the label--looked safe. I had a violent MSG reaction. When I called the customer service line, the gentleman there confirmed that there was MSG in the product, but it was referred to as 'textured vegetable protein'. He told me a few other buzz words to look for. I've since found many, many more by doing some research on my own.
Back to the original question--use good fresh ingredients, high quality, fresh herbs and spices and you won't need to 'enhance' the healthy natural flavors of your food with a chemical additive like MSG.