Drive both back to back, and you'll see the new one has superior power, comfort, safety, and fuel mileage.
Compare a Boeing 707 to a 787. Seriously, there's no comparison.
However, either you appreciate the old one for what it is, a time capsule of what was cutting edge for 1970, or improve upon that old relic, which is what the whole Pro-touring movement is all about. However, that will cost you an easy $100k for it to be close to everything that new $50k SRT can provide.