Our Lake Bled and Ljubljana Slovenia from Trieste small group trip (8 people) with Koper Tours was wonderful. It was a bit of a drive there (from Trieste), but the vehicle was very comfortable and our tour guide, Dan, gave us some interesting Slovenian information along the way to each stop.
Then at Lake Bled, Dan gave us an excellent overview of the area, as well as when we were in Ljubljana where he walked us around the main historical area explaining many details of the town and its buildings, bridges, other structures and the history, then we had some time on our own. We especially enjoyed the view from the castle. This was a fantastic first Slovenian experience for us.