My body likes Hammer Gel, and in fact gets on well with all the Hammer products. In fact it was a bit distressing to find, on the recent Davis Double Century, that the only nutrition items available at the checkpoints were . . . real food.
I'm so used to Sustained Energy, Hammer Gel, Perpetuem, etc. that a double on real food was a different kind of challenge! True, I had a couple of packs of Hammer Gel Expresso in my jersey pocket in case of emergency.
Overall though, I got on okay with real food, no issues, no problems. Still, I agree with jppe that Hammer nutrition works best for double centuries, and even for shorter recreational rides (okay, doubles are recreational too), short rides, etc.
Rick / OCRR