Webb, one of the best pitchers in the National League before seeing his career end, at least for now, on opening day in 2009, represents an extremely low-risk and potentially high-reward arm. While Rockies fans understandably want to see the club do more than go after another reclamation project, one has to admit that the team has enjoyed some success in that department, as Renck notes.
Regardless of where he signs, or even if he signs, Webb isn't going to be what he was prior to the injury, especially now that age isn't on his side. So, any weird expectations should be tempered well in advance of the season. However, if he is healthy and is able to command his pitches, his history of being able to induce groundouts indicates that he could be a good fit for the Rockies. So, to Webb and the Rockies, I say: Why the hell not?
Karstens, however, is not a good fit. Dan O'Dowd has mentioned on multiple occasions that the team is looking for pitchers with good ground ball numbers, and with the exception of 2011, that attribute cannot be used to describe Karstens. As much as I'd like to see Karstens and Jeff Francis combine to produce one of baseball's all-time best-looking duos in terms of pitchface, I fear an acquisition of the DERPy one would also produce disastrous results on the field.