Their products are definitely quality and it's a trusted company, however not a big fan of the stim- free. Their pre extreme is great, similar to our N.O. SPOT with the cluster dextrin. Having that carb source is a game changer and won't diminsh the effects of any of the other ingredients. If you're looking to go stim-free, you should still consider compounds like dynamine and teacrine that promote energy but don't raise blood pressure or HR.