I've been outta the loop for a few years but have recently purchased an '09 690 but I'm not so current on whats good in tire choices anymore. I'm looking for a 90/10 or 80/20 on/off road tire thats SM specific, and when I say SM specific I'm talking about bike weight. I don't believe your standard sportbike tire is appropriate for a 300lb supermoto, the carcasses are too stiff and the compound is too hard. Back when I had my 610 I ran the SM specific Distanzia and loved them, they are no longer being manufactured and the replacement Avon now has does not specify for lighter bikes.
I just put a set of Heidenau K73's on my 2010 690SMC and am loving them. They are a supermoto specific tire. For reference, I put about 6 sets of Distanzias on my old DRZ. Feel like the K73 is a better tire actually, as unlike the Distanzia when you've got it at full lean, the steering feeling doesn't get vague as you lean it further and approach the limit; they just feel planted all the time. and they're no where as heavy as the distanzias were.
I don't know how long the K73's are going to last- they don't look like they will but my buddies swear otherwise; been hearing that you get about 6-8K km out of a set. I did a 1000km weekend ride with lots of gravel roads and twisty highway and a buddy's showed a bit of wear, but definitely not what i was expecting, and he was just railing the gravel turns while i was definitely more sideways sliding all over the place and at the limit with my old Q3's. The K73 is a rain tire shape with a street compound rubber for longer life, but my buddies have them on their XR650R and 610 and were raving so I joined them. I was laughing as i came off some down to the belt Q3's that were sliding everywhere on the soft setting on the KTM, and the shop gave me the standard take it easy for the first 100km tire talk, and after the first two corners, the Heidenaus were stickier than the bald Q3's... it was really weird having a tire that was so planted that i felt like i could corner and drag my elbow on, with the temperatures just a degree or so above freezing and snow on the road shoulders.
So far found the K73's to be very sticky, instant heat up, look great, unreal lean angles. Check them out if they sound interesting.