I'm fully in camp Rick when it comes to lodging -- two-to-three star quaint hotels in the middle of the action -- but if I had four-star money to spend and I aimed for modern int'l appeal, I would put the Occidental in Ljubljana high on the list.
https://www.barcelo.com/en-ww/occidental-ljubljana/?
We spent a few nights there earlier in June on the OAT Adriatic tour, and the location is perfect: there's a Lidl supermarket right underneath the building, the summer stage plaza is right around the corner, and everything a tourist would be interested in is a short walk away. Great transit and car service access, too.
Breakfast buffet is sumptuous. Fresh, high quality pastries, fruit, cheeses/cold cuts, and plenty of hot items of an egg/bacon/pancake variety, and they will do custom omelettes if you ask. Hand fruit to stick in your RS civita for later in the day, too.
Rooms and hallways are creepily hi-tech, with lights that brighten and dim based on your presence, separate toilet and shower stalls that have cheeky cartoons on the wall but no pesky shelves or hooks to get in the way of your rain shower faucet. There was an inspirational message to start off your morning written on the ceiling above the bed. Mini-fridge is cleverly built in to the independent-standing sink and vanity mirror stand.
They do the hand towel and bath towel but no washcloth thing. Clothes hanging rail and that vanity are in full view of anyone entering the room, which seems like an odd thing to me as a 'merican. Maybe if I was Dutch it would make sense to me.
Anyhoo, check it out in case there's a deal or you just don't like quaintness.