Meh, I've had a few different Cliff bars and they're all to sweet for me. But the packaging is pretty robust. Take sunflower seeds for example. A 3.5 oz bag of sunflower kernels has 595 calories, and 525 calories is from fat! I think that's outstanding............carbs might be easier to access but the energy from fat will last longer. Plus it satisfies your hunger better IMOHO. Nuts pack a lot of nutrients and calories for a small amount of bulk, plus they generally keep pretty well. You will need a bit more water to process them though.
I agree with you on the sweet and carb issue. I maintain my weight by exercise and controlling simple carbs in my diet. I gave up Clif Bars for that reason. I tried something new (to me) recently. An Atkins 'Sweet and Salty Almond Crunch' bar. It is 1.4 oz (40gr)has 7gr protein, 1 gr sugar, and 4gr net carbs. It has 200 calories of food energy, 140 cal from the healthy fats from nuts and sunflower seeds. It costs a buck, is lightweight, tastes good (especially with coffee or tea), and keeps for months in its mylar packaging. If you buy a package and don't like them, I would be happy to eat the rest for you.