Fantasy Baseball: Edinson Volquez or AJ Burnett?

We will be posting our second half starting pitcher rankings in the next few days, and after ranking the starting pitchers, I saw this question on the ESPN chat with AJ Mass yesterday:

john (dc)

would you rather have volquez or burnett the rest of the year?

AJ Mass

(11:15 AM)

Burnett, but it's only the unknown that keeps me away from EV. If Volquez pitches well in his first start back, he instantly jumps over Burnett, but I need to see it with my own eyes to feel comfortable about that.

I ranked Volquez about spots ahead of Burnett, maybe 25 spots. I think Volquez has pitched well enough in the minors to be ranked in the top 50 or so starting pitchers for the second half. Could that be because I own him in two leagues? No. Volquez was a solid starting pitcher when he was healthy back in 2008, when he went 17-6 with over 200 strikeouts.

Who would you rather have for the second half?