I haven't had any experience with Wowboy.
I have had most success with clear, mint juices. Dark, sweet juices tend to be carto killers. At least in my experience. Although I think I've read that fruit juices (excepting citrus) are easiest on cartos.
Nimrod said that he loves it in post #34 of this thread: Smileomizers Burning really easily? Although it doesn't really say how well they interact. At the end of the thread (post $#64) Mr. Morandir addresses Wowboy.