I ride a 1997 Jamis Quest for a commuter. I use a clamp on rear fender for the rainy season. I hate commuter specific bikes. I could perhaps go to a cyclocross bike, but I really like my roadie for commuting. I run a 25 rear and 23 front with no rack or panniers. I will be using it for the occasional race, but overall I am looking for a good investment and a slight upgrade in performance and reduction in weight that new technology will bring. I think the Gunner would be a good investment at $800, but I am little concerned about the mixing of two steels. I like the Guru because of the reputation and the one steel frame, however that comes at a $2000 price tag, but that $2000 also includes a decent fork and custom fitting. The Gunner has stock options and no carbon fork standard. Custom Sizing brings the price to $1200.
Comparing the two it almost seems as though Guru come out on top as far as bang for the buck. The only other consideration is that the Gunner would look better with DT shifters and the Guru may not. However, that is not really a factor for me to consider as long as they both have DT shifter bosses. I do not use STIs.