The CCT just keeps tension on cam chain to ensure it from stretch, and to keep it in time. If it would get really bad, the chain can slack too much and cause stretch under heavy acceleration. It can also cause the cams to skip time. This is rare, but internal engine damage can be very severe if cams skip time, or if chain breaks. Expensive to repair also.
CCT's very commonly go out on pre '03 honda F's. A friends '02 F4i went through 3 last summer in 2400 miles. If you hear a F4i with a bad CCT, you'll remember distinctively what they sound like! Yet i haven't heard of honda having many problems with time skip, or breaking chains, so this goes to show how rare it can be. I'd say about 3 of 5 Honda 600 F's i hear have bad CCT's!!