I have owned a couple of convertibles and again never really suffered from any of the problems. Had a couple of sticky roofs after they have been up all winter which is easily resolved with a little lubrication. I have also been caught out many times with the roof down and it starts to tank it down. If you are on the motorway just speed up and you don't get wet!!
I personally love convertibles, nothing finer than driving with the roof down and hearing the car and the feeling of infinite space. In the summer I don't even get angry in traffic jams with the roof down, just put the seat back, arms in the air and enjoy the tanning experience!!