Back in the 2.1/1.95 days, I used to prefer a softer tyre than most, around 50psi. Mostly to give the joints a bit of a break. I used to get a lot of flats.
Now I'm on 2.4/2.15, I actually run them harder, about 80. I found that big tyres flex too much otherwise. Also, I think a big tyre has more give than a narrow tyre at any given pressure - so I can now run harder pressures than before and my knees are still happy. Consequently, as well as more grip, I also have more speed on bigger tyres - not what I was expecting! I resisted big tyres for ages, but now I'm so converted that I'm really thinking about 2.4/2.4, even more speed...
Also something else I only just appreciated recently is the effect these huge new tyres have on bb height and head angle. 2.4/2.15 Rubens slacken your bike by nearly a degree, and raise the bb height by 0.4" compared to 2.1/1.95. And the wheel diameter is more like 21", getting closer to a 22" cruiser.