I can ride this one all day with nary a twinge, even in my relative moto-senectitude (been riding 27 years). A Harley ride from here to Philly would require a double cheek replacement. I'll stop in Gettysburg for the 140th anniversary of "Pickett's Wheelie" :)
And there ain't a Harley on the planet I can't smoke in 3rd gear. That leaves 4th for the Beemers and 5th for the serious riders :)
It's smooth as a baby's butt - no noticable vibrations other than a small buzz at the handlebars at about 4000 RPM in 3rd.
(edit: out of curiosity, I located pics of all the bikes I've owned.)
[image|http://www.kzrider.com/forum/viewthread.php?action=attachment&tid=50&pid=146||||]
1976 Kawasaki KZ400 - classic lines, 1st bike, rode it until 400cc was boring and sold it to buy an HP-41C.
[image|http://home.earthlink.net/~richandmags/Bikeside1.jpg||||]
1982 Kawasaki KZ750 - ugly but durable. Lots of great mammaries - er - memories.
[image|http://www.bosurobbikes.20m.com/images/im002647.jpg||||]
1985 Honda VFS1100 Sabre - a beast - 33" seat. Made any Harley look like a Spyder.
[image|http://www.halflifesoftware.com/cycles/xs7502d2.jpg||||]
1977 Yamaha XS750 Triple - weird and fun
[image|http://bmw.mc.no/bmw/r75_6.gif||||]
1976 BMW R75/6 - "Die Gummikuh" - the rubber cow. My favorite bike, slow but German. I called it "Bertha" and it looked exactly like this.