We have just put Solarfocus CPC panels on our roof (built in on a new build). They contain a vacuum like the tubes but have the appearance of flat plate panels. They are also the thinest (I think!) panel on the market. Extremely happy with the look, although we haven't plumbed yet so can't comment on the way they work, but they are meant to be as efficient as the tube system. To the best of my knowledge they are also the only panel on the market with a guarantee against corrosion from salt (if you live by the sea!)