The ride is pretty soft compared to my former C6 and current IS-F. Handling is very good, but the car does feel heavy (could be that I need to lose 40 lbs )
It shouldn't feel heavy compared to an IS-F. That thing outweighs the Boxster by about a half of a ton!
If you're looking for a crappy, abusive ride, that's easily fixed with some stiff springs! But don't confuse that with good mechanical grip, they don't necessarily go hand in hand.
I had a 1974 2.7L 911S a while ago and now have a 2002 Boxster. The 911S was my daily driver while the Boxster is a project car for my son. Love both cars for different reasons as well as hated both cars for different reasons.
You seriously cannot go wrong on either car as long as you find the right car to fit you and your budget. Keep in mind that a 1980 SC is now over 30 years old and will provide you with a whole new realm of potential issues.