It depends on who you're asking. It's a hard to play card, the "pros" consider it a noob card because it's hard to win with, but not impossible. If you manage to figure out the a deck with good synergy around Yubel, you can both be proud of your work and effectively shut up those who consider it a bad card simply because they are too lazy to think about the meta-box.
Also, welcome to Slifers.