Stayed at the Grant Union - Executive in June 2007. Had a wonderful room even though it was next door to the entrance to the pool. Room was clean and equally spacious to an American hotel room. The hotel is nicely situated near the center of Ljubljana. Easy to get to the tourist areas downtown. Front desk personnel were very helpful arranging for drivers to the airport.
Check experience of various people with the hotel: http://www.tripadvisor.com/Hotel_Review-g274873-d456147-Reviews-Grand_Hotel_Union_Executive-Ljubljana.html