Bought a few packs of each and tried them both last week. The first time I tried the GU, had to go to the bathroom quick and stay there for a while, LOL. Second time, it was fine.
But I like the Powerbar gel a little better because it's not as thick as the GU, and I like it during my rides for that reason alone... GU is too thick when I'm right in the middle of a 40 miler. But after my rides, I'll take the GU to help with the recovery. Did that a couple times, and so far it seems to work pretty well.
Both cost about the same at my LBS.
What do you guys like?