I tried the original formula - I was even part of Biotest's giveaway as part of their kickoff marketing, and it did absolutely nothing for me. I'll be trying the new formulation once I've finished my MD6 next month.
I'm not sure why MD6 works so well for me, but it's an amazing mood enhancer for me. I tried Spike after everyone lauded it at the Staley seminar and it didn't work for me either. shrug