Between the two, I always thought Kirby Smart was slightly better (and keep in mind that I am a Vols fan), however Jeremy Pruitt was very close to Smart.
Smart's defenses at Georgia have been great. Interestingly, outside of Alabama, Georgia has been probably the most consistent program in the SEC when it comes to being good but they have yet to win a Championship compared to others such as Auburn, Florida, and LSU. With all of our disappointments, we still have a more recent title than Georgia.