The difference between the Miele Guard S1 and the Guard S1 Comfort lies mainly in the features and operation. The Guard S1 is the standard model with basic functions and a normal AirClean filter. The Guard S1 Comfort offers additional comfort features such as a higher quality telescopic tube, an improved filter and some extended accessories. Technically, both models are similar, but the Comfort is designed for more convenient handling and slightly better air filtration.