I've used the shuttle once. For the life of me, I can't recall why (I rarely connect through ORD since I live here). Anyway, what others have said is accurate. I suppose that since you have to pass E3, you could take a quick look and see what it looks like, but otherwise, give yourself 10-15 minutes and enjoy the exercise. Just don't get carried away following the herd and find yourself on the outside of security.

The new security area and connection area between T1 and T2 is nice. The lines are generally very short unless they have decided to run a large group of seldom-flyers through there. Check in at T1 (if you do OLCI, you can check your bag just outside that security area, btw), go through security, turn left through the bridge and you're on your way to T2. Retrace your steps on your way back, enter concourse B and head for the dinosaur. At the dinosaur, head down the escalator to concourse C.

If you're not checking a bag, do OLCI and you can go straight into T2 security . There used to be a small flock of Easy Chickens in T2 in case you need to reprint a BP, but otherwise, you've saved yourself a few steps, although T2 security can get periodically goofy.