Food could be the only issue. Breakfast is very simple, we stayed there for 2 nights and it was the same every time. We also had dinner included, but went there only once, as it left a lot to be desired. If you have an option, especially travelling with children, I'd recommend to include only breakfast and have the rest of meals at the nearby restaurants which offer a variety of local and sea-food dishes!
All the staff was nice and kind, helpful and attentive to your requests. Location is great, beach, shops and restaurants are very close, but at the same time it's a bit aside from all the events happening in Portoroz. If you are travelling with children, you will not be disturbed by music and noise at night.