I had cheng shins on my 79 cb750F. They were fairly new and on the bike when I bought it. Personally I did not have a good expirence with them. In fact I think I would have gotten better traction if I took a massive greasy shit and then wrapped it around the bare rim. At least I never had to worry about highsiding, there was never enough traction in them to throw my large ass over the other side.
the problems I had were:
1) they were out of round, not bad but the the crown of the tire was off center a little.
2)Every hard corner was like a lesson in flattrack racing. I had the rear step out on me a couple of times when I was leaned over, once even at 30 mph.
3) they were no better in the wet. They had a decent tread pattern but seemed to get worse in the wet.
I put avon venoms on that same bike and I swear I could use the bike to do a heart transplant because it carves like a scapel.
I understand not every tire is perfect and I understand I could have easily had a defective set or the PO could have super cheaped out and bought demos or leftovers but I just don't like them.
Incidently, when I was in law school, one of the cases we studied regaurding products liabilty involved a DOHC cb750, a horrendous accident in california caused by tire failure, and a set of Cheng Shin tires installed by a honda dealer. I'll see if I can look up the case when I get a moment. One more reason I stay away.