It is quite variable. I've had a number of experiences at ORD where I arrived (and it has happened arriving both B and C), was sitting in E+, made a quick pit stop, and then walked purposefully, but fairly leisurely to bag claim, only to find my bag already going around the belt (and no possibility that it arrived earlier than me). On the other hand, yesterday, MCI-ORD, I had to wait at least 25 minutes (long enough to go over to the Bagzilla machine and check and see if my bag preceeded me to ORD). Yesterday was nasty at ORD with weather and tons of mis-connects. What I have found is that any flight with a lot of connections means that ORD-bound bags will take a while to get to bag claim.

I was pleased to see that my Priority-tagged bag was the first on the belt from MCI when they did finally come out.

I was also pleased to see that UA finally replaced the bag claim overhead monitors.

The Bagzilla machine is interesting. Essentially, it is an Easy Chicken that has been reprogrammed to read bag barcodes and report status or allow you to file a claim. Hope I never really need to use one.