There is now a section for equipment reviews.

http://www.microstockgroup.com/reviews/index.php

If you don't find the equipment you have on the list you can ad it.  Hopefully it will be useful for some people.

Depending on how much it is used, perhaps in the future it will be further integrated into the rest of the site, where we can add equipment we have to our profile and see which people are using a certain lens etc.

That's a nice addition, Leaf.  Maybe there is a way that threads about lens/camera tests (like your tests with the teleconverters) are linked to this area?  I for one always like to see real-life tests with image samples.

yeah, that would be a good idea.  Something like the 'related topics' thing at the bottom of a thread except on the equipment pages.