S5481 Earth vs S5281 Callisto
images from manufacturer

Both of the Miele S5281 Callisto and S5481 Earth belong to the Miele S5 serials, the major difference between these 2 Miele S5 canister vacuum cleaners are:

:::::::::::::Powerbrush:::::::::::::
The S5481 comes with the SEB217-3 Powerbrush which is electrically-driven, it has a 10.5″ wide brush roll, it is self adjusting for carpet height, Miele recommend it for smooth floors, low to medium pile carpets/rugs.
The S5281 comes with a wider power head, the SEB 228 Powerbrush that has a 14″ wide brush roll, it has 5 height settings, Miele suggest to use it for cleaning hard floors, medium to high pile and plush carpets.

:::::::::::::Suction Control:::::::::::::
The S5481 has 3 stage suction control via a +/- foot switch, whereas the S5281 has 6 stage adjustable suction settings that are controled via rotary dial power selector.
And the S5481 also features AutoEco Setting that automatically adjust the suction power when transition between hard floors and carpeting, this will save you time and energy. The S5281 does not have this feature.

:::::::::::::Filter Change Indicator Light::::::::::::::
The S5481 features filter change indicator light that tells you when to change the HEPA filter while the S5281 does not comes with this indicator.

:::::::::::::Motor Protection Indicator::::::::::::::
S5481 features thermal cut off indicator while the S5281 does not.
However, both of them have the motor protection fuction.

:::::::::::::Color::::::::::::::
The S5481 Earth is Steel Blue Metallic while the S5281 Callisto is Deep Black.

:::::::::::::Price:::::::::::::::
The S5481 Earth is about $80 more expensive than the Miele S5281 Callisto (prices checked on 05-14-2013)

If you know more difference between these 2 Miele S5 models – S5481 Earth and S5281 Callisto, please share your comparison here. Thx.