I too use search and enter to navigate quite often. But I also use middle mouse button to open targets in background. This doesn't work when there is no target. And I think every link should have an target. So buttons are all right if they just modify the content of the page. Buttons for opening new pages are bad. Anchors opening new pages (usually sized pop-ups) just by javascript, having no real target are horrible and I want to punch someone responsible every time I see something like that.

Funny enough, the google plus linked above is horrible at this.