Yes, bright side.....but sad side that there will be less ferries and you will have to deal with the buses along the coastal road!
You say October, so I guess the magic day is October 1st (and not November)! All I knew it was the beginning of a fall month haha I guess the changeover in spring is May 1? UGH haha
It was once the end of February, temps in the upper 60s and I left the house with a long sleeve shirt on and a scarf "just in case" and ALL of my friends were worried I would get sick and die because I didn't have a jacket on! I even got weird looks!
I think Sorrento will be more relaxed than summertime and handy for daytrips, Capri, the ruins, and Napoli in particular, though I would hold your plans in your hands very loosely depending on the weather.