The CT-5 is an excellent take-along chain tool. As another poster already mentioned, if you don't do too much wrenching it could be your only chain tool. In 15+ years of riding I have only had two chains fail on the road. While rare, I was glad to have the CT-5 when I needed it.

Just FYI..Here is a little take-along tool kit I put together that includes the CT-5.

http://www.instructables.com/id/Bicycle-Mini-Tool-Kit/