I went to San Francisco having never been before and as a lone traveller. The travel agent assured me that I would like this hotel and that I would enjoy it more than going to a big chain which I would normally do.

The hotel is very clean and comfortable, safe and secure. They had a way of making you feel welcome and at home. The standards are high and your room is very clean. My bed was very comfortable indeed. The business centre was free and had excellent internet access. I would say that it was excellent value for money and the staff were very friendly and extremely helpful. It felt like a family business as they were all so genuine. The only thing to let it down was the café at breakfast time. They need to have extra staff then to clear the tables and bring the food out. As I had to wait 20 minutes to be seated when there were 3 empty tables that just needed to be cleared. But the staff were very apologetic and quick once inside.

I am so grateful to the travel agent as I was right in the heart of things and easily able to get to all the attractions and find great places to meet the wonderful locals.

Stayed at the Rex July 8-11, 2008. Two adults, two children. We had a room with two double beds. For an old hotel in the heart of the city I was pleased with size of the room. The beds were quite comfortable, the room was tidy, and the bathroom was clean. After our first day seeing the city, we returned at about 7:00pm to a room that had not seen maid service. We informed the front desk. They were apologetic and offered to have it cleaned then, but, being tired and with 2 young kids to tend to, we declined. The rest of the stay was pleasant, however I would have expected some sort of gesture (comp the in-room movie we watched or something) for having forgotten to clean our room.
The location of the Rex is nice if you want the Union Square scene. There is a Cable Car stop at the corner of Powell and Sutter, which is very convenient. We also found two charming, good and kid-friendly restaurants within a block of the hotel (Max's and the Cozy Cable Car Cafe).
It is a busy part of town, and there is a strong contingent of homeless folks approaching you on most corners. A bit annoying after a while.
I would likely stay here again if I crave the Union Square location. However, next visit...if it's just me and my wife...I will opt for a B&B in the Cow Hollow / Pacific Heights area. I bit quieter there and, IMO, a better selection on restaurants.

Great hotel, great location just off Union Square. Staff very friendly and helpful - nothing a bother. Only drawback no tea/coffee facilities in the room but they do have free tea and coffee in the bar in the morning.

My room was just beside the lift but you wouldn't have known as never heard anything and I wasn't an early riser. Lots of people I met were leaving early so you would have thought I would hear them.

Hotel restaurant good value and food excellent.

We stayed at the Rex for 6 nights at the end of June 08. The location is fantastic, assuming you prefer Union Square to the Wharf.
The decor is slightly tired, but it's clean and comfortable. The bed and pillows were really comfortable, the bathroom was large and the shower worked well. You get a bathrobe and slippers, for those who love those extras! There is a minibar fridge in the room, but no tea/ coffe making facilities - although they offer free tea and coffee every morning from 5am.
Our room was at the back of the hotel on the second floor and was so quiet that we were able to sleep with the window open all night (there was no noise at all).
The staff are genuinely friendly (as opposed to fake Californian friendly) and want to help you. Each night between 5 and 6 you get a free glass of wine, and after that drinks are pretty reasonably priced (for a City centre hotel). We didn't eat in the restaurant so can't comment.
On the day we checked out they let us have our room for an extra couple of hours at no charge.
One thing that hasn't been mentioned on trip advisor (that I can see) is that if you go to their website and let them have enough notice, they will arrange a free of charge personal tour with a Golden Gate Greeter. This is really worth doing - our guide was great and spent half a day showing us around - you tell them what you want to see/ your interests - and they tailor it to you.

I would definitely recommend this hotel.