After swatching a second time (successfully, I might add), I cast on for my test sweater last night and got through roughly half -- about an inch and a half -- of the ribbing before it was time to call it a night.
It's been a while since I did a sweater in the round (or, for that matter, one in regular old Cascade 220), and I'm rather enjoying it. The first couple of rounds are a little slow going because the stitches really have to be coaxed to move around the needle, but after that it's pretty much smooth sailing.
I think I may take tonight off to ply up some handspun, but this sweater is going to be my go-to project for the next couple of weeks (the shawl has been promoted to lunchtime knitting in order to get it done). I have two days off from work this month that I'd planned to spend at my LYS, so I can see the sweater getting done in no time -- probably just in time for a major midsummer heatwave!