Maybe good before a run, but unless they have Protein in them, not as good after workouts compared to protein powder.
I would say Energy Bars are probably a 6 / 10. Barring any major issues like loads of poor quality Sugar in them, they might be alright, but not in many circumstances.
I'd choose protein powders over bars. The simple reason being that it digests alot faster. Plus what Bossman said, some bars are full of horse piss ingredients. If you're gonna buy loads of it, choose the all natural ones.
It is a good idea to eat an Energy bar about an hour before a run or workout. I have tried many kinds, but have found one that I really like - Kashi Go Lean Protein/Fiber All Natural Bar - Peanut Butter & Chocolate flavor. One bar has 290 calories/48g carb/13g protein/31g sugar/6g fat. I usually only eat half of a bar and save the other half for later. Alot of energy bars are just cleverly disguised candy bars, but this one seems genuine.
Another good energy bar you might try is Zone Perfect Dark Chocolate Nutrition Bar. It is really good and only has 190 calories/6 grams Fat/14 grams Sugar/12 grams Protein/22 grams Carbs. Yummy!