I haven't done too much heavy duty touring and am a bit on the smaller side (5'10", 190) but have had a blast doing 150-300 miles at a clip in and around the Rocky Mountains. Other than a bit of a performance loss from lack of O2 at the highest mountain passes I have had outstanding fun on my '02 America/Master and can take ANY canyon road and leave those bigger displacement bikes in the dust.
BTW, who considers riding at 100+ mph "touring"? You don't get to see much at those speeds.
