As a gold Expedia member for the last 9 years and spending a lot of time in Stockholm I would say all round this is the best hotel to stay in.
I've tried pretty much stayed in every other hotel in central and would put this at the top of the list.
The location is perfect if you are looking for central location, with it being next to central station for the subway or arlanda express.
The rooms are clean, modern, have nice shower products and sound proof windows.
The gym is to a good spec for a hotel gym and always very quiet.
The staff are helpful.
Breakfast always included which is good.
Book in good time to get best price, leaving it later the price will jump up.