I think that Dr. Atkins allowed both Stevia & Splenda.
Also, I read an article by Bev Laumann of the Interstitial Cystitis Network.
She happens to be very sensitive (like the miners' canary) and she said that she found Splenda to be even more tolerable to her than Stevia. She also got very good feedback by IC sufferers regarding Splenda.
The articles are on this site (just scroll down to the pink-bar - Year 2001):