We have a large conservatory and I did have a quick look at this not long after moving in as ours is relatively old and noisy when it rains. Think glass option is very expensive though, even though it's probably the best option.
Looked at firms that offer tiled roofs too. Look great and easy to maintain etc, but that starts to get complicated as the weight can be an issue depending on the construction of the conservatory.
Glass is considerably heavier than the poly, just be careful that the roof can accommodate the extra weight. It may have only been designed for the poly roof.
If you look at the tiled roof ones, some of them are lightweight tiles and not concrete roof tiles as you have on your house, often they are pressed metal. Often the roof and ring beam will be removed before these composite style tiled and insulated roofs are installed.
I have a glass roof in my conservatory and it's a lot quieter than a polycarbonate one, especially in the rain.
Ploycarbonate can become discoloured and brittle after a while. And is also susceptible to hailstone damage.
As has been mentioned, make sure the extra weight of the glass can be supported with existing frame. Some companies may advise their own complete roof structure, which will look better anyway.
Conservatories aren't always too hot in summer and too cold in winter - with the right heating and a decent blind system.