Bazep - you would keep a (small) CF card solely for saving your custom settings on, they are quite cheap to buy, and worth saving one purely for settings if you find them useful.
loplyg - there are a huge number of settings that can be changed on the cameras other than just speed and aperture, unlike in the days of film. Think focus points, custom flash settings like manual or commander mode, white balance, af activation button, iso setting, auto iso or not, bracketing, etc, etc, etc. Some of these settings matter less if we shoot in Raw, but lots of 'togs shoot away happily in jpeg, and get amazingly good images.
The very fact that so many respected forum members have custom settings saved to their cameras demonstrates how useful the custom settings are.
....and is f8 the only setting you use for landscapes?