Pros: He was signed to only a 1 year deal, hasn't balked since 2011 (really, there aren't many positives with him, so I'm reaching).
Cons: Hasn't been decent since he was named Fausto Carmona back in 2010, low strikeout rate, gives up lots a hits. He's basically the Dominican version of KK, but slightly worse.
WSBGMs 2014 Projections for Roberto Hernandez:
7-13, 25 GS, 147 IP, 109 K, 4.93/1.38