I am currently staying at this hotel as a regular guest for the coming months. I have sampled a lot of the services and thought it would be good to share my experience here.
About the duplex suite. I would say that this is a nice room type, but it is not my favorite. i have only stayed in one with no roof window. This meant that it was rather dark in the second floor and in combination with the challenged AC system, it was also rather warm. I understand that other duplex rooms exists with a roof window. I am not sure it can be opened to alleviate the temperature issue. Other challenges include a narrow staircase leading to the upper level which is not so easy to climb if you are bringing your suitcase. Also, my upper bathroom only had a bathtub with no shower capability - the walls were to slanted to allow for you to stand up in the bath.
I personally prefer the junior suites (x06 and x07). Two of them have balconies, which might be fun when it is not so cold outside.
Just this past week the lobby area has been partially re-done. Essentially they banned the Sheraton Link computers from their previously central location to the far end of the lobby, against the wall. This opened up a lot of space for additional seating in front of the bar area. At the moment they are still testing whether or not they will provide table service from the bar. I approve of the change as the area now feels much more open.
Right before this renovation they also added a space walled off by glass for a souvenir shop. However the shop inside has not been set up yet.
I have to say that the staff here is very, very good. They are all friendly and make an attempt to learn the names of the guests. If you run into issues they look for an amicable and practical solution.
I would like to see them make their gym a bit less cardio-intensive. I understand from their management that this could be changing in the medium-term.
Overall I would rate this hotel as one of the best overall Sheraton experiences in the chain for a solid hard product, excellent and competent service and good value.