I pretty much embody Retrobike. I own nothing newer than my 1994 Klein Quantum II road bike. My other main ride is a 1983 Raleigh Super Course 12, updated, repainted and S&S coupled. I also own a 1984 Trek 520, 1993 steel Stumpjumper FS, 1974 Raleigh Gran Prix, and various and sundry cruisers, winter bikes, two Raleigh Twenties and 3-speeds.
The Klein is cool because it's sleek, gorgeous (Sea and Sky paint -- anyone else familiar with that one?), stiff, solid, light and responsive. It was not expensive when I bought it. Mind, this is not the top-line Klein available at the time, but the frame was only about $800 in 1994. Contemporary titanium, Cannondale, high-end Trek OCLV, European and American lugged or tig'd steel were all much more money and while I'm sure they were and are fine bikes, nothing else available at the time offered the combination of assets for the money that the Klein did, to my way of thinking. It did make me faster -- show up to a group ride on a flashy (though not too flashy) Klein and you'd better be ready to work! (I had a friend tell me my bike was "glowing" during one ride ... but this was after I'd waxed it twice
) As for the ride, I've never thought it was too harsh. It is stiff, but not dead-feeling like the OCLV bikes, and while it's not springy like my beloved Raleigh (a Cadillac by any measure), it does have a very lively and responsive feel to it without beating me up. And to this day it attracts a lot of positive attention. The only mark on the bike came from a handlebar strike suffered during a bone-breaking crash many years ago. The bones healed, mostly, but the ding is still there. No matter.
Good discussion! Maybe I'll get motivated and post a picture ...