Polycarbonate is available clear or opaque. The main advantage is that it's very difficult to break, whereas toughened glass can shatter if it gets an impact from something hard and sharp.
However, polycarbonate scratches, discolours and tends to attract algae far more than glass, and is also more difficult to clean. Double glazed glass panels should insulate just as well if not better, and the latest solar-reflective types are quite effective.
So I'd definitely go for glass, with blinds if necessary. We've had that arrangement for 15 years and everything is still in good order.
