There are more important aspects than color or appearance that need to be considered when selecting such an addition to your household. Performance, size, weight, number and type of available filters and the accessories can be very important factors.
Select the optimal size with the available storage space in mind. For a smaller flat, a smaller device might make more sense.
If the housework is usually done by women, weight can be a deciding factor. Moving, pulling and coordinating a machine for hours, weight does make a difference.
There are four common kinds of filter systems. Ones with textile bags are not suggested because of the inconvenience of cleaning. Paper bag models are not the most environment-friendly, while there are backers of both water-filter and dust tank models.
Check the floor brush if it contains a strong metal inset or not. Also check for wheels and interchangeable brush/no-brush system.
The hose should be 360° rotatable and made of unbreakable plastic, though it is hard to make sure of that at the point of purchase. If the shop assistant allows you, twirl the hose and then check for any marks. There should be none.
The most reliable tubes are the ones made of metal. Telescopic tubes are more than practical for storage and comfort reasons.
A drape cleaning brush can be a very useful addition.