Great views of the city, but that's about it...
I really wanted to be blown away by the Mark Hopkins but sadly was only impressed by the fantastic views. The hotel facade, the lobby, and The Top of the Mark (restaurant) were all great but sadly not enough to make for a great hotel stay. I love older hotels and the Mark Hopkins InterContinental seemed to have a ton of charm especially when you see it from the outside. You then get into the lavish and luxurious main lobby and expect more from there but that's pretty much where it ends. This is an InterContinental and that's exactly what you can expect. 
We booked a king bed view Club InterContinental room which was an upgrade because of the size and the view of the city . The room was average size, about 350 square feet, was clean, and had very bland brown / taupe / black furnishings. The bed was very comfortable and the Frette sheets were a nice touch. The weather was nice and warm so we had the air conditioning on in our room but although we had the thermostat set to 60 degrees Fahrenheit (16 C) it was always about 70 degrees or higher and seemed too warm. NOTE: We were on the 12th floor and had a fantastic north facing view.
Be forewarned that the elevators are very small (they only hold about 6 - 8 people max, and if you or another guest has suitcases then prepare to wait for the next one). If it's peak hours for the Top of the Mark then be prepared to wait as long as 10 minutes for a free elevator (to be fair, this happened only twice, the rest of the time it was fine). It's not a huge deal but it was annoying. 
The Top of the Mark is expensive, and yes, it's a tourist trap, however, it is well worth it to go there for a drink ($14) because the views overlooking the city are truly spectacular. You can clearly see both bridges, Alcatraz, Yuerba Buena Island etc. 
The staff were courteous and helpful and were able to answer any questions we had. 
The location is great, Nob Hill is a very nice, very safe neighborhood perched atop the city. The streets around it are very steep so be prepared for that as well. It's a 10 minute walk downhill on Powell (or cable car ride!) to all the best shopping in SFO. There is also a cable car on California St. right in front of the hotel that will take you to the The Emabarcadero district on the water (Ferry Terminal).
Overall I really wanted this hotel to be more than it was, more than an InterContinental, and to rate it higher, but I can't give it an above average because it really is just an average, rather expensive hotel with really wonderful views of the city.