I too have found this a pretty quick connection, even if you need to get over to Concourse C. ORD is quite nicely laid out and signage is large and user-friendly. As mentioned before, AC gates at E1 or E2 which is very close to the exit concourse of Terminal 2. A quick left turn, walk around the corner and you are in Terminal 1, Concourse B. Halfway along on the left is the underground passage to Concourse C, helped along by moving sidewalks under the famous neon lights. I have made this trek (actually from the outer edge of Terminal 2) over to Concourse C in 10 minutes. If you have 30-60 minutes between connections and your YYZ-ORD flight arrives on time, you are laughing.

I love ORD. Great departure lounge display boards, lot's of windows to airplane watch. It's just not a great place to spend the night.

Good luck. I'll be making the same trek in late April.