I've been using GAT pre-workout for the last 15 months. Still enjoy it, still works for me. I may try the C4 though if it makes you hot and sweaty. Isn't that the idea of your workout?
Also using this for my post-workout:
Recently added this:
And just started using this on Friday:
Been using this for about 4 years and the only thing I could recommend to anyone because this seems to work for everyone!