And on the nutrition alternatives note...
I really prefer the 'less sweet' gu flavors: salted watermelon, peanut butter, espresso, even salted caramel can be ok. Maple bacon was interesting, but maple sweet.

We have found taking a gu, one package of blocks (citrus type flavor), and several ounces of instant mashed potatoes does the trick for us. The very not sweet butter and salt flavor of the potatoes is heavenly around mile 8.

We tried the stingers, but I find them too sweet and dense. Our go to pre-race fuel is a piece of PB toast and a 5 hour energy. It takes me several miles before I can get in the groove if I have too much in the stomach at the start.
For drinks, we usually carry two bottles (7 oz ea?) of lemon lime gatorade on our belt, mixed at half strength. In a properly supported race, those last all run. On course, I always grab water. When it is hot, I drink a few ounces and pour a few ounces over my head.