Tourmasters are working out fine. I bought them based on reviews on thegsresources.com. Lot of of 'zukes on them and they have earned a really good reputation.
I haven't pushed them too hard---but not because of the tires, but the brakes. Had a significant problem when i rebuilt them this summer and it took months to figure out why I had little braking power. Another ADV'er (bwringer) fixed them just a few weeks ago and now I am not pushing them because I don't like to push cold tires too hard.
Have my eye on another oddball Suzuki for next summer. A friend has a '91 VX800 that I may buy. Just trying to convince the spouse that I need another strange bike in the garage.