I find it interesting that when linear trackers first came out, they were advertised as the next best thing to sliced bread. But look at what turntables are available today: not many linear trackers at all. I think the hype outweighed the benefits.

There was a company Finial something or other that had a laser-based turntable system a while ago. I believe they went out of business because the technology was too expensive to support the volume they needed to survive.