It does depend on your riding position. On a racing bike, more of your weight is on your arms, and you're generally pedalling harder, both of which reduce the weight supported by the saddle. Conversely, on an upright city bike, you tend more towards sitting back on the saddle, and on a touring bike, you won't be pedalling hard for long periods of time, so you would want a more supportive saddle. On my commuter bike, I use a fairly hard, sprung saddle. The lack of padding on the saddle allows your 'sit bones' to take your weight more directly, and the springs take up some of the road shocks that would otherwise be damped out by padding. 'Back in the day', a lot of bike saddles had some form of springing.