The Post-Gazette's comparison of Virgil Vasquez to Josh Fogg is a useful one, I think, because the two pitchers seem to have similar skill sets, and because Pirates fans understand who Josh Fogg is. I want to add a little addendum here, though, because the Fogg comparison may suggest expectations that I really doubt are there.
This is Vasquez's age-27 season. By the start of Fogg's age-27 season, Fogg had won 22 big-league games. And Fogg has never been designated for assignment three times, as Vasquez has this offseason. Personally, I don't think Fogg was ever very good, but even expecting Vasquez to have Fogg's modest career would be expecting way too much, and I would be very surprised if anyone in the Pirates organization expected that of him. They're just looking for a bit of extra depth, and a team in the Pirates' situation has to take any opportunity to add anyone who comes cheap and potentially start in the big leagues without completely embarrassing himself. Vasquez is no Josh Fogg, but he's better than, say, Yoslan Herrera, and that's probably all the Pirates expect him to be.