My not-so-humble opinion of that wiki page is that it's corporate-vetted bullshit.
I see no reason to add a neurotoxin to my food at all, even in "moderation".
It sounds like you're not as sensitive to msg as many others are, and that's great for you. For myself there is no reasonable amount, because every time I eat food with it added to it, it makes me physically miserable.
If you investigate alternative sources of information, the fears that people have are not based on ignorance. In fact I would say that it isn't fear, but information and experience that has led people to want food without chemical additives, especially a neurotoxin that is labeled as natural such as msg. I know it occurs in some food naturally and that's fine, just don't dump it into mine as a toxic chemically-equivalent additive.
All the articles on this page are pretty well-researched with citations:
http://www.naturalnews.com/MSG.html