I've got a very old 600SS that needs new tyres. I mostly ride on country lanes with the odd bit of dual carriageway commuting (no track days). The 600SS is old and slow - so I guess it would be waste putting on the latest sticky rubber.
I just had a brand new set of Diablos fitted for £190. This is my 3rd set now and I have always been happy with them. I commute to work in most weather (excluding snow) and have never had a problem. Usually get plus 5000 miles and a trackday before looking for a new set.
I'd agree with all the other comments about Diablos. I had a set fitted to my 1994 750 SS and they transformed the handling. £180 fitted ride in/ride out. I've had another set put on my recently acquired 851 SP2.