All over, actually. I trawl forums, review blogs, &amp; news articles. The more the better.<p>&quot;Professional&quot; reviewers in particular fill a gap- some of them have had their hands on just about every &lt;vacuum&gt; ever made, so they can provide something frequently lacking on storefront reviews, an opinion well informed by experience with many alternatives.<p>I also like sites like DxOMark, which provide raw test data that you can review yourself.<p>The main theme though is just, many sources. Any one person can be bought, but not the whole internet.