If memory serves, he was sent a Surface Pro 2 by Microsoft. And a Surface Pro 3. I don't recall if he was given the original Pro or if he bought that one himself.
Either way, I would view his endorsement and any other interaction with Microsoft with a shaker of salt; this is not at all dissimilar from the multitude of celebrities whom Samsung sends the latest Galaxy phone in a swag bag in order to get a "I wasn't paid off, I just really like it!" endorsement. His celebrity status commands him a certain amount of influence for whatever judgment he proclaims on the Surface (note, for instance, how every post he makes about it ends up on the front page of HN). I can guarantee if the same points were raised by a normal person who paid for the thing on their tumblr blog, there would not be a team of Microsoft engineers rushing to fix them.
Either way, I would view his endorsement and any other interaction with Microsoft with a shaker of salt; this is not at all dissimilar from the multitude of celebrities whom Samsung sends the latest Galaxy phone in a swag bag in order to get a "I wasn't paid off, I just really like it!" endorsement. His celebrity status commands him a certain amount of influence for whatever judgment he proclaims on the Surface (note, for instance, how every post he makes about it ends up on the front page of HN). I can guarantee if the same points were raised by a normal person who paid for the thing on their tumblr blog, there would not be a team of Microsoft engineers rushing to fix them.