Clif bars are cheaper than candy bars and don't hurt my teeth or make my tongue feel coated and gross after eating a couple. I can eat one clif bar an hour and drink nothing but water and be fine for up to 12 hours of riding. The variety of flavors are ok, they all have the same base flavor but are different enough to keep from getting too boring.
When it's very hot sometimes it gets hard to eat anything so I'll skip a couple of hours of eating and have a soda and then a large water bottle with one Nuun tab. This seems to reset my stomach and after this gets in my system I can go back to eating. I used to eat Powerbars as well but they seem to have ceased production and are only available in peanut butter, which I cannot stomach long term.
I can't really see anything objectionable here:
Are Clif Bars Good For You? Breaking Down CLIF Nutrition
But what do I know. I hate eating real food on rides, I've tried it several times and it doesn't work for me at all. So YMMV as always.