At just one or two blocks off union square, and at about 60% of the price of hotels with similar levels of quality/service/location - there is SO much to love about Orchard Garden.
First - LOCATION - You are right in the middle of everything. Very walkable to just about everything. As stated, Union Square shops like Williams Sonoma and Macys are right there (as are many great restaurants. Chinatown is on the end of the same block. Cable Car line to Fisherman's wharf - 2 blocks. The piers - 4 blocks. BART (to airport and beyond) 2 blocks.
Second - ROOMS/SERVICE - When we booked, the front desk asked if we'd like a towncar from the airport (since it costs the same as a cab b/c the hotel has an arrangement with a service). Of course, we said yes. Our room was a queen-size with ample space - bathroom is very private set off from the main sleeping area. It's also quite large for a standard room. As you'd expect from SF it's very eco friendly, your room key slides into a panel by the door and it controls A/C and lights by automatically turning them off/on when you leave/return. Big comfy down (or down alternative) comforter on a great bed. Quiet atmosphere - not a peep from the hallways or neighboring rooms.
Third - EXTRAS - The restaurant downstairs is delicious. Not San Fran's absolute best, but far better than most hotel restaurants. The rooftop terrace is also very cool - very neat views of the financial district and a great place for chit chat and such. This is the sister hotel of "The Orchard" just down the street - which allows you to also enjoy any of the amenities at that hotel as well. You just need to bring your room key or ask the front desk to call ahead for you.