Matt I am running Avon's on the R100RS, they were also a forced choice as no tyres were available in my favourite brand (Pirelli) to suit the 19" front.
I have recently had to opportunity to run 600km up on them over 2 days. They do not react the same way as the Pirellis but I guess they are OK.
Let's get real here, at 65 years old I am not up to scratching to anything like the extent I once did, I would call myself "brisk" these days rather than "fast'.
So, whilst not as confidence inspiring as I might like they will stay on untill they reach their useby date and then I will see what else is available. I really do not do many Kilometers on the old bikes these days, in fact over the last 12 months I have probably done 3 times as many miles on the DRZ as I have on the ready of the fleet combined. Of the runners next would be the KLE, then the GSA, followed by the R100RS. I am a little embarrassed but it more than a year since I last rode the R65/860.
Hmm, New Year resolution, improve health and ride more.