Has anyone made either the NFSC or Penny's recipe with Splenda rather than sugar??

How do they turn out??

I tried splenda with my sugar cookie recipe and it was all crumbly, so I got splenda sugar cookie recipe on the web, and it was okay, they didn't rise, but were okay. I put splenda in my Magic Bullet (blender) to make powdered splenda for RI, and it was kinda weird to work with, like sort of stringy, but it was okay. I used Wilton's spray food color on cookies and accented with the RI. So No sugar in the cookie at all.