We were staying with a group of 7 colleagues in this apartment for 5 nights during a conference in Grand Hotel Bernardin in Portoroz. This apartment is nice for both holiday and work trips (near conference hotel).
The owners of the property (Lara and her husband) were very nice and helpful. When we unexpectedly arrived very late at the apartment, she was very flexible and came up with a good solution for the keys. Also during our stay we could contact her any time if we had questions or needed something.
The apartment is perfect for a group of 6-8 people. There is one bedroom with a bunk bed, one bedroom with 3 single beds, and one bedroom with a double bed and a single bed. There is one bathroom with a bath, shower and toilet, and another separate toilet. The kitchen is fully-equipped and really has everything you need. There were even some basic things like salt, pepper and balsamic vinegar. The best thing about the apartment is its terrace. It is very spacious, has a great view and there is a gas barbecue that you can use. Finally, there is a swimming pool (shared with a family living downstairs).
The only downside is that the road to the apartment is quite steep. It's also not in the middle of the centre. As Lara already warns on TripAdvisor: a car might be recommended. But for our purposes (walking up and down to the conference hotel, about 15 min walk) it was definitely doable and we could manage without a car.