Personally I like Petit more, so far he has pitched great. But it kind of depends what you could get in the 3rd rd compared to the 5 rd also, if it's a big jump in talent it might be worth it.
I saw Edwin the other day and he looked pretty good, Petit has just been more impressive.
I'm sure someone will find this interesting, found it on RotoWorld.com
"A high-tech lab in Birmingham, Alabama, revealed why batters have so many problems hitting Yusmeiro Petit, even though he doesn't reach 90 mph.
The slow-motion cameras, which take pictures more than 16 times faster than a standard video recorder, showed that Petit manages to keep the ball hidden longer than other pitchers. Petit finished second in the minors in strikeouts last season with 200."