Spent one night there early last week.
Plusses:
Nice hotel literally RIGHT in the city center. A 2 minute walk to the Tyr Church and the central square of Prague 1/Old Town.
Check-in was a breeze, with a personal handshake and enthusiastic welcome from the General Manager of the hotel, who was on duty when I arrived. She personally introduced me to the concierege, who offered to help with cars and anything, both giving me a business card with a direct line. I did not use their services, and some may find the treatment over the top, but I was amazed at the level of treatment personally.
Nice bar and restaurant with decent food, excellent by most Marriott standards, but middle of the road compared to what we procured outside of the hotel. Prices were slightly steep but understandable.
We had a late (9:00pm) flight on to our next destination and had nothing to do for the afternoon. They graciously extended the rooms until 4:00pm local ("because you are Platnium, we can gladly extend your room until 4:00pm"), a courtesy they extended to my co-traveller, who is barely a Silver. Then, when we told them we wanted a 7:00pm car to the airport, they extended our executive club access until 7:00pm.
Hotel had good car service available, although it was a little expensive compared to a cab: about $10 US more expensive, but the cars are nicer and the driver doesn't talk on his cellphone, with the radio on, racing trains up and down hills like the cabbie does. I guess you get what you pay for...
Rooms were nice but standard Marriott rooms.
The minuses:
Cost, cost, cost. Internet was $33 a day. The rooms were $300 a night. While the local market may support this, I had a hard time understanding what that $300/night got me. $33 for internet and poor wireless service just felt like a ripoff.
Cheers,
-Andrew