I've been three times, in May, June and July and I have noticed a huge surge in the throngs of people in the city the further out we get from the war. It actually takes at least a decade after something that disastrous for people here in the U.S. to get that association out of their minds. It's gone now and it is crowded. It is gorgeous there however, just amazing. I've stayed at the Excelsior as well and was most unimpressed since at that time it was supposed to be their best hotel. They have added a number of great places since then. We've also done the renting rooms from the ladies where the boats come in. That was, OK I guess. One time it was interesting and fun, one time, uncomfortable.
I too would recommend Lokrum Island and also the other nearby islands you can get to on the "fish picnic" boats, where they cook out on the boats as you spend the day touring the islands. Great fun. Split is lovely as well, as it Brac island off its coast, with the country's most famous beach Zlatni Rat.
Do your research and you'll be fine.