Looks like just another fad product to me, ie just caffeine and whatever tailored herbs they decide to throw around it (which are usually don't contain a therapeutic dosage of whatever compounds they're touting, so you get almost nothing out of it). It'd likely be more cost effective to just do the oldschool caffeine and aspirin stuff if thats the route you're going to go. Unless you can get your hands on some ephedra mixes, those were the only ones that actually worked (trust me, I tried them all at one point) but are illegal now.
What I'd like to see is a high ephedra/argenine combo mix, that'd really knock your socks off (if your heart didn't explode).