Great value
First and foremost I think this hotel is great value for money - the location is perfect and I know when I was looking, other hotels in this area are much more expensive. 
My husband and I took MUNI from the airport to the hotel without problem at all. It is a short walk uphill from the Powell St station, which was fine for us but if you had tonnes of luggage it might not be so great, and it's a busy street with lots of pedestrians to navigate around. On a side note, we also took MUNI back to the airport very early (maybe 5am-ish) and there were some homeless and drunk people out but we felt safe. 
We had a room on a high floor which was great and nice to look down on Powell St and towards Macys. There is no aircon, although there is a fan. This was sufficient for us in September but not so sure if it would be enough in the middle of summer... And to be honest, when we had the window open it was too noisy for us to sleep. The rooms are small-ish but still totally functional. We had 2 suitcases and there was space for them. The beds are also small-ish (perhaps a double or a small queen) but we are used to a super king bed at home. The bathroom was the only thing I thought was a little dated but it was clean and totally fine. 
The free wifi was great!
Powell St is a great base for shopping, restaurants and transport and I would highly recommend this hotel as an affordable option to enjoy all of these things.