Jack's place was wonderful and it will be my first choice for a return visit. The space is modern and spotless. The building has a security guard in the lobby. The check-in procedure was straightforward. The bedroom and bath next door were very private. The bed was comfortable and the storage space was convenient. The room has a wall of windows and is airy with a view. The shower is a delight. Jack was friendly and helpful.
The street is just off Market. Market is fine to walk during the day. I also walked Moscone to Jack's on Howard during the day with all my luggage with no issue. Like many parts of San Francisco, I wouldn't walk the streets late at night. I had no issues taking a Lyft to the door in the late evening. The fact that it's on the flat part of San Francisco is also nice. I've stayed all over the Union Sq & Powell area in the past and you have to contend with hills! I was going to Moscone every day. I did the straight walk in about 20 minutes. I tried the one stop on the BART for variety and might have shaved off a few minutes.