There are a lot of individual and group tourists in Kotor (mainly Australian, Russian and French), but they are not too imposing and I mainly heard Serbian/Montenegrin during my short stay in the town. One thing you should certainly do when in Kotor is climb up the 1,300 'steps' (sometimes steps, sometimes broken rocks, sometimes nothing) to the Kotor Fortress for some amazing views over the Kotor Bay. It is extremely hard work and tiring so bring water and food with you! Flip flops were not the ideal footwear for that adventure...
I also took a short trip to Bar, which is a bit further down the coast towards Albania. I wasn't impressed. The food I had was terrible (but that could be down to the particular 'restaurant' I chose) and the beach was not particularly nice and lacked amenities (apart from a rather unsafe looking fairground and an ice cream kiosk selling black market cigarettes). The new town does feature some rather astounding architecture with three dome-shaped buildings housing some shops - apparently the locals refer to them as the 'Three Albanians'.
Ideally, I would have loved to have spent a few more days relaxing in Kotor and perhaps visit some other towns along the coast. The people are friendly, the food is good (just follow the crowds and you're in luck if you're a seafood fan), and the prices are not extortionately high considering the large numbers of tourists descending on the town every summer. So, if you have the chance to visit Kotor, I would say go for it.