There seems to be alot of wonder about Owen and C-3PO remembering each other, or C-3PO remembering Tatooine, etc. but no one seems to wonder about how Darth Vader snags Leia's ship over Tatooine and doesn't wonder what she's doing there. He was born on Tatooine. His mother died there. He's connected to this planet, but you'd never know it based on his reactions. I can't believe that Vader, who got all wistful when he sensed Obi-Wan on the Death Star, didn't sense him on the planet below, or at least wonder what brought Leia to his homeworld. Who would be there for her to deliver the Death Star plans to? If he sat down in his meditation chamber for a few minutes, he probably could have saved those poor sandtroopers some work.
Also, if those plans were so important, why did he leave Tatooine to bring Leia back to the Death Star? He could have interogated her on the Star Destroyer? If he'd still been orbiting Tatooine when the sandtroopers updated their progress with tracing the Droids to Owen and Beru, Vader's internal alarm bells would have probably gone off about a connection to himself still down on that planet which was going to prve a problem to him later.
Maybe he's just not sentimental. Maybe his injuries gave him brain damage as well as several extra inches in height.