I did a concrete counter top about six months ago. I didn't do the integrated basins and instead just left a hole to drop a stainless steel sink in. The project was more work than just slapping a prefab counter top down. It was however, much cheaper than a prefab. Total cost came to about $50 by the time I purchased the concrete, stain, edge forms, and concrete board backer.
It's been working well with no appreciable visible wear. If I were to do another counter I'd rent/borrow an insertion type concrete vibrator. I used my hammer drill with a bolt that I put a slight bend in to vibrate the concrete. It took a while and didn't get every little crevice filled. I'm calling the imperfections character. Another option is to get a concrete mix that doesn't require vibrating.