I stayed there for the second time within four years for roughly a week when visiting our czech office. The rooms are huge, very stylish but still cozy. Definitely amazing!
Unfortunately I have to say that the service and the friendliness (at least at the reception) is below average. At least for some people of the staff. There where some really nice and friendly ones (on our checkout), but also some unkind ones.

I reserved two non smoking rooms for me and my colleague about 4-6 weeks before arrival and I was given a smokers room. As a returning visitor with explicitly reserving a non smoking room I expect to get one. Or the information in advance that there are no more non smoking rooms available.
After (literally!) 2 minutes in that room I took my suitcase and went to the reception again asking for a change.
The staff member was a irritated and made me notify that. She even told me that she'll ask the cleaning staff to come again and then the smell would be gone. Sure! They can turn a smoking room into a non-smoking room with one cleanup. Must be magic. Allegedly they had no other free room.

After arguing for some minutes she finally promised to find a solution. So I got a new room - on the next category. Didn't she mention they have no other free room?
My colleague who was travelling with me got a free upgrade to the next category without any additional charge directly at the check in.
Basically I'm ok with that even if I still would have gotten the "small" room, but why did she refuse it to a returning customer when he has eligible complaints regarding the first room?
Be honest to your guests and if you are upset and/or irritated be more professional.

Anyway, finally the second room was good, though it (and I assume all the others as well) didn't have an A/C. As we where visiting in early summer it already got pretty warm.

I used the hotels gym twice and was pleasantly surprised of the quality of the training gear they have. But also there is no A/C (or it was turned off the whole week). So it got pretty warm and steamy.

Breakfast is above the average with a good quality and choice, me and my colleague definitely enjoyed it.

If I have to travel to our Czech office the next time I'll try the Golden Fish once again because the overall quality is really good. It's just some people of the staff that should work on improving their service and kindliness.

We used to stay here everytime we had a conference with Mladí konzervativci. Everything was absolutely perfect and well organized. If you want to arrange a business meeting, Golden Fish is the best choice.

This hotel is fantastic and definitely worth a stay. He only downside is the restaurant. The atmosphere is great, but the service is dismal (even by Czech standards). The waiter (Michal) forgot several orders, did not return to serve drinks and never asked if our table wanted dessert before the restaurant closed. No apology offered. The steak was also inedible, but no waiter in sight to return it. This is not the first time this has happened at this restaurant. It is a real shame as the hotel itself is really good and let down by the restaurant staff and food.