Harshness can always be cured by using wider tires. But it sounds like you're looking for the same fit you have now, and the same degree of shock-absorption, but in a lighter, faster bike.

I would avoid gel saddles and shock absorbers in a bike that will be used for long road rides. Gel tends to compress soft tissues and cause numbness; springs soak up your energy as well as that from bumps.

You should try to analyze what it is about your current bike that makes it compatible. Look at the chainstay length and seat- and head-tube angles, and compare them to modern bikes. Do they more resemble a racing bike, or a touring bike, or a cyclocross bike? You'll find that the geometry has as much to do with the comfort and stability of a bike as anything; the short-wheelbase, agressively-angled racing bikes of today are fast and light, but offer an entirely different riding experience from the classic sport-touring bikes of the 70's.

Personally, at 52, I find that the bike I look forward most to riding is my Airborne, which is set up as a light touring bike. Fairly wide tires on touring wheels, medium-long chainstays, wide-range gearing, titanium frame, chro-mo fork. It's not terribly light, but it's extremely comfortable whether I'm commuting or riding centuries. I do have a lightweight racing-style bike which is fun for fast Sunday training rides, but there's nowhere on it to pack my lunch.

I think you need to tell us more about what you want the new bike to do, and about what you like and dislike about the old bike. (Most people don't associate the words "speed and thrill" with "touring bike.")

RichC