Not been to Ljubljana but have been to Slovenia the past 3yrs for hols.
3yrs ago we spent 2wks in the mountain area of Bovec.
2yrs ago we spent 2wks at Lake Bohjin
Last yr we spent 1 week in Croatia by the sea and then transfered up to Lake Bohjin again for a week. Would(will) be going back again, off to Canada to visit friends this yr.
Only dissapointing place we visited was Lake Bled, too touristy for our liking.
If Ljubljana is as nice as they say then I would certainly visit but maybe stay somewhere elst, heard it can be a bit pricey as can all tourist traps. Maybe go to Marribor and travel down to Lub??
The people are friendly and speak good English, some learn 3-4 languages at school due to the Italian/German influences from the war times apparently.
N.B. Latst yr the exchange rates and general cost of living rises had hit the Bohjin tourism by something like 30% according to our hotel receptionists. It was notably quieter 🙁