I rode the U-District today. It is the first and only bike with skinny tires that I've ever ridden. I almost bought the bike, but I was worried that some of the parts were way sub par. Maybe they aren't. I'm not up on what is quality right now. I didn't think that the brakes worked very well, but the last bike I just sold a bike with Avid BB7's, so I'm used to really good brakes (oh, that bike had tires that were 1.5" wide, Primo Comets, so that was the skinniest tire I had ever ridden).
I like the upward sloping top tube of the Torker, the Redline 925, and the KHS Urban Uno, but I don't know **** compared to members here.
I still may purchase a U-District, just in case I puss out on riding a single speed for transportation use. Also, it has bosses for a rear rack. I can use it for a utility bike if I like riding a single speed, and want to upgrade my go-to bike.
I guess I'm going to take a look at the other bikes that have been mentioned on this thread.
I'm still very tempted by the Redline 925. I like the colors, that the brakes and rims are not painted, and its geometry. I don't know enough about components to comment on them, but a guy at the LBS had some good things to say about the rims/hubs. He was probably just talking up the bike.