None. I do look at the test results of new tests from time to time. But I don't take that much notice - I'm not going to suddenly switch my av becuase it performed poorly in a test.
I prefer to check internet security forums like this rather than trusting any comparative tests that am not sure enough if they're driven by under the table negotiations just to make their product stand out among the rest. (The bigger the pay the higher the rank, if you know what I mean.) But, it is just my very own opinion...
I generally look at the support forums: - unresolved issues (how long are they sitting on something) - slow/poor customer service (took you 12 days to reply back, ouch) - customer reviews (well not to many bad reviews, couple trolls). I figure most of the av detection tests are bought out with money for good publicity. Not saying I ignore the possibility of false customer reviews.
