I have and use both. I use the Glass as a gel substitute. It's supposed to be similar to Curve's curly pudding. I believe that's what they used before they created CP. Stretch can be a deep conditioner.
New natural as of August 10th; after 28 months of transitioning
I used the glass many years ago and did not like it. I smelled fine and the consistency is fine but it dried my hair out something fierce after only a couple of uses. I think this happened with other woman as well who used it too. So... I don't recommend the glass at all.