Being an adopted Cornishman I have visited the Scillies both by fixed wing aircraft and helicopter (Tresco Heliport).
IMHO the biggest problem there has been the closure of St Mary's on the sabbath! You are allowed to depart at a certain prespecified time but they are by no means open. This seems very antiquated to me and has certainly prevented me from visiting on several occasions.
The islands can be windier than mainland airports because of the local topography (read - flat).
The PA-32 mentioned has not been the only aircraft to be bent on the humpbacked runway there in the recent past
- hence the warning in Pooleys.
The problem with not landing at the correct speed on the numbers is that as soon as you crest the hump you are accelerating again - so approach slowly and if the speed is too high then just go around and have another go.
SB