Thanks for your replies. We had originally ruled out the tilting panels on cosmetic grounds, but have been a bit bothered recently about what happens if you need a repaint on the roof, Andy what happens if they were to peel away etc. The air draft has been suggested as a major advantage of the tilting panels, but then equally people seem keen to suggest that we go down the flat, stick on route.
i think that on reflection, taking in to account the “bang for your buck” argument, we may stay safe and go with the A frame mounting. We aren’t live aboard, and so will really only be looking to the sun during the warmer months.