If German language is not an issue you might want to look at these sites:

Ciao (German test site with lots of reviews)

Testberichte (German site, not so many reviews)

I also often go to Amazon (co.uk or .de) just to start off with.

If you do your research on a German site you will have to take into account that some manufacturers' products may not be available in Switzerland. So it's best to do a quick CH-google for availability, before reading all the reviews.