If the argument for and against getting a convertible comes down to boot size, just check out the available boot space in a Porsche! At least the Carrera has a back seat (sort of!) that can be used to sit an overnight bag on. The Boxster only has room for a shopping bag in the front boot.
There's enough room in the Astra for my wife and I to go on a motoring holiday for a week or more . . . her stuff in the boot, my bag of jox'n'sox on the back seat!
But, as has been said earlier, you don't NOT buy a convertible because of the lack of boot space.