I just had a pleasant stay here a few days ago.
1. Confusingly the rates are in euros, but Croatia doesn't use the euro and didn't see any dual pricing at all, unlike in some countries (e.g. Hungary). The prepaid rate I booked was €83.91 per night, but my card statement showed a charge of HRK 603.90 converted to £72.79. This was £1 to €1.153 but the pound to euro rate did not improve beyond 1.125 between booking and staying. So I thought that maybe a hotel tax would be due at check-out, but I wasn't asked to pay anything.
2. I booked the basic room and don't think I was upgraded. The hotel seemed very full and my rate was quite low so not complaining. Others have said everything that needs to be said about the rooms.
3. In the room were a personal handwritten welcome card, fruits, 2 small bottles of wine, 2 large plastic bottles of Jana water (not glass, so actually practical to take out), and some chocolately snacks.
4. The Sofra Bosnian restaurant mentioned in the OP is still there and excellent. We got takeaway costing 110 kuna for 2, and was too much to finish. After ordering, we visited the supermarket through the revolving doors by the Asian restaurant, and the food was ready on return. With our meal we had the wine gifted by the hotel, which was pretty nice. A burek ("pie" on the English menu) was 25-30 kuna and would suffice for one, if really wanting cheap yet good.
5. Breakfast selection was limited compared to some other DTs. Chicken sausages tasted a bit weird. The teapots only held enough water for one cup. Egg station was nice. Main issue was small size of the restaurant. At 7.30am they had to tell people to go away and come back in 10 minutes. There is an outdoor seating area but nobody seemed to want to sit there, might have been a bit chilly. We had to sit at a "communal" table each morning because all the smaller tables were occupied. Overall still good.
6. As mentioned by others, the location is a bit off. There seem to be many offices in the area so if you have business nearby it would be great, but not as good for tourists. The Canopy location is much better, but I walked past the construction site and it didn't look anywhere near to being ready to open in the next 3 months.
As mentioned, tram 2 does take you to the main bus station and the main train station. You can buy 30-minute tickets from the newsagent kiosks for 4kn each (15kn from the driver). Paper ticket validators are only at the very front and sometimes the very back of the tram. There are smartcard validators throughout the tram, but I didn't investigate this further as you probably won't take the tram that often unless you are repeatedly travelling far.
I had several issues with the trams: when a ticket is only 4kn then the hotel is just a bit too far to walk, yet I ended up walking half the time.
This summer's European heatwave still seems to be ongoing in Croatia, and Google maps reporting of Zagreb tram times is inaccurate. The first trip to the hotel, I couldn't even push through the hot and smelly crowd to reach the validator so it was a free trip. The second time, I missed the tram by 30 seconds because Google said it was coming in 2 minutes. There is no shelter so I just walked rather than waiting under scorching sun for another 12 minutes (you can walk under shade of buildings).
The third time, I took a different tram because number 2 was not coming for 15 minutes, but the driver was told to finish short and turn back, so got turfed out and it was faster to just walk back as my ticket would have expired by the time the next tram + one transfer arrived at the hotel.
7. Everyone in Zagreb I encountered spoke English well, even old people. The only unpleasant experience was getting accosted by the clipboard beggars around the cathedral.
8. The hotel's airport transfer is now 140kn while the bus from the bus station remains 30kn. Worth considering if you have 4 people, or 3 with luggage, or hate public transport.