My judgement is based on following grounds:

Volkswagen Polo
Exterior design, cabin looks, built quality, room and road behaviour are its strong aspects. Less convincing are some of the engines and the rather high prices.

Toyota iQ
It represents a display of imagination and space exploitation in a format of minimum size. The high price reduces the scope of its potential customers.

Opel Astra
Heritage from Insignia shows in design, as well as in the technological content. It is a neat improvement over the precious Astra, but not in the roominess.

Citroën C3 Picasso
In little more than 4 metre, the design allows optimization of inner space, in the cabin and the cargo area. The fresh style is very convincing.

Mercedes E-class
A product well made, with a high level of technology, especially in safety matters. However, the style looks aged and has lost some quality.

Peugeot 3008
In the plus side, the new approach as a mid-size MPV with new technological points. No much flexibility in the cabin and a boot not big enough.

Skoda Yeti
The Czech manufacturer uses perfectly the sinergies inside VW group to develop an interesting compact SUV, with good quality. Little new in a crowded segment.