To add to the anecdotal evidence: my wife is susceptible to migraine headaches. Taking Aspartame, she’ll get one every four or five days. Off Aspartame, she’ll get one every six to twelve months. Eating an unknown food containing Aspartame will usually trigger a migraine in 24 hours.
Needless to say, my wife avoids NutraSweet at all costs, and has gathered considerable research on it.