I tried Size-On for awhile, and wasn't that impressed. Tasted like arse, and I didn't like drinking it during my workout. However, I'm a big fan of SuperPump 250. Yes, I think the ads are a joke, but it's the first pre-workout NO/energy supplement I've used that gives me the boost I need without the jitters. Plus, the pump I get is definitely noticeable vs. when I wasn't using it. For the record, I've been using it about 4 months and will continue with it.