I have mostly got around the 10,000km to 13,000kms mark on the ST11, some in ST13 sizes, and have been happy with that (after years of less than 5000kms in the good old days) but some of the newer tyres seem to grip as well or better and get great distance.
Best tyre so far for me has been the Shinko Verge at 17,000kms front and back. Pilot Road 2 on at the moment but only 5,000kms on them. Grip, ride etc fantastic, but distance yet to be determined.