We visited Croatia last year in July.
Okrug Gonjii is isolated and not the place to have night fun (few bars,restaurants and no club), but it's the perfect place to relax.
Trogir is a few kilometers far from Okrug Glojii and you could take a boat until midnight, but after that hour you had to walk to get back. Cabs were difficult to find and quite expensive.

We had made the reservations 2 months before for villa Paula in Okrug Gornji.
When we arrived there the administrator of villa Paula told us that there were no rooms available for us even if we had paid them in advance. They had booked the rooms twice and those who arrived first got the rooms.There were many tourists in the same situation and many of them ended spending their vacation in some other lodging with worse conditions than they had paid for.
Fortunately we were a big group and he was forced to find a sollution for us because we refused being sent to different places of the resort.
We were very angry and after a few hours of terrible fight he came up with a sollution for us - Villa Kruna Grada which was much better than Paula anyway.
We had our meals at Paula and stayed at Kruna.

Still, I could not find an excuse for their rude behaviour and I wouldn't recommend this place to anyone not because of the place, but because of the staff's attitude which was terribly wrong and unproper.