There are tons of different kinds of pre workout. Most of them have a ton of caffeine, but I've found that it's not crazy noticeable unless you don't drink much caffeine day-to-day. Aside from amping you up, the caffeine improves blood flow. Not sure what you were expecting, but the marketing is usually a little extreme.  C4 is pretty solid. I like one called ENGN. Muscle Pharm Assault is also okay. Try different varieties and figure out what you like. A few of them have ingredients that are supposed to help you get a good "pump" or increase your muscular endurance. If I'm considering a new one, I usually read up on it in bodybuilding.com and look the ingredients up online. Amazon is a great place to buy most of them, especially if you have Prime. I actually prefer pre-workout without caffeine, because I often gym late and it keeps me awake. Lately, I've been blending my own using supplements from Bulk Supplements (again, on Amazon). It's cheaper and I know exactly what I'm putting in my body, as opposed to relying on a "proprietary blend."  I'm currently taking creatine daily (not really a pre thing but w/e), and I measure out and take beta alanine (endurance at high reps), taurine (generally good for you and eliminates what would be negative long-term side effects of the beta alanine) and citruline maltate (endurance/pump) as a pre-workout. Definitely do research before blending your own cocktail, though.