clear polycarbonate greenhouse

hi just been looking at clear polycarbonate greenhouses and was wondering what peoples views are  of clear or twin wall polycarbonate. I like the look of the clear as its like glass but safer. but hubby says the twin wall will  be better for colder temperatures
which one have you got and what do you think?

Thanks for your reply Ice just read your thread on greenhouse poor you but with a happy ending thankfully. it has definitly given me more to think about ie bracings and fixings.  I still think i will go polycarbonate way rather than glass as have young grandchildren riding scooters ect passed where it will stand so safer than glass. cant decide on clear or twinwall polycarbonate though. Anyone got any views on either.
thanks