Calm and laid back but still a tad too touristy. There is no definitive 'wow' sights though I remember the Il Vallone dei Mulini (Deep Valley of the Mills) which is unique to Sorrento in the Amalfi.
Insider Tip:The most scenic part of Sorrento is the bus trip out of Sorrento towards Amalfi. Watch the bus schedule though! While there are a couple of nice lookout points, they are mild compared to seeing Napoli from Castel Sant Elmo, or the dramatic hillside buildings in Positano. Sorrento also have cheaper accomodation options than the rest of the Amalfi.