Vivaldi Conservatories have just carried out the installation of my P Shape conservatory. The project can only be described as a success. We took a long time to make up our mind regarding the design but they were happy to let us visit a couple of completed installations to help us decide. We have gone for a glass roof, because we do not like the rain noise you get from polycarbonate sheeting, also the glass has a better heat retention performance, which is very important to us with the room facing due North. The company do offer the full range of glazing options, including the Pilkington Activ self-cleaning, which we did not order, which is my only regret as I am finding the regular deposits the birds leave a bit annoying.
We have had a full project, including plastering, electrics and laminate wooden floor. The only snag we had had was the French doors which needed an adjustment a couple of weeks after completion but this was soon attended to and has not been a problem since.
We use the room as a dining room, so we need to use it all year round, it certainly is fit for that purpose.
My advice would be to take care to ensure you get a conservatory that looks right on the house and is thermally efficient, I would honestly say that a specialist firm like Vivaldi Conservatories could help you achieve that.