The firmer the bushing is, the less deflection it'll have, in general terms.
Side effect is less absorption of vibration and noise.

Closest I can offer a comparison is 2 different vintage TransAm race cars we restored & ran some years back, though the cars themselves were different:
1. Ex-Penske/Roy Woods Javelin, no rubber in suspension/steering
2. Privateer 69/70 (raced as both), had some rubber in suspension/steering

The Javelin was more consistent & confidence-inspiring when pitched around on-track vs the Mustang.
The Javelin also had more power, so it would seem logical that if the two had equal power, the difference would be even larger.
Both cars were optimized as far as settings, though the Javelin was originally a further-developed car.
That's with both cars having their necks wrung; at less intense driving, that edge didn't seem very noticeable.
My buddy, who'd done well in SCCA A/Sedan in SoCal, and in other stuff like pavement Sprint Cars, called the Mustang a pig in comparison to the Javelin.