Stay Away
When I booked this hotel in May, I called to ensure the renovations would be complete by the time we visited San Francisco (June 30-July 5). I was assured that the construction would be done by July 1. Not even close. Better estimate is probably September 2012. The lobby bar is completely ripped apart, as is the fitness center. On top of that, construction workers monopolize one of the two elevators most of the time, even on weekends, so you'd better get used to waiting. Our hotel room was on the third floor, with no stair access to the lobby. The room was renovated and big enough for a rollaway bed, but the A/C was not working. Thankfully, it was cool during our stay but the room still needs air flow. So we opened up our windows (as most guests did, by the looks of it from the street) and listened to street noise all night. Not good. And finally, the housekeeping staff is horrible. We had to repeatedly ask for towels for 4 people and to have our tub/bathroom floor cleaned. They did not sweep or vacuum the room; only after we complained. And they didn't restock toiletries; again, only after we complained.
Bottom line: There are better hotel options in the Union Square area. We walked by several each day and wished we'd chosen differently.