Definitely all valid points. For me, using bike share systems is ultimately dependent on how long I'm in a given city. I use bike share when I'm in Boston for conferences, because like you my trips there are point-to-point and rack (station?) coverage aligns with my routes. Back home in the bay I don't feel any urge to use the bike share.
The fleet of bikes being poorly suited for SF is really my biggest gripe with the system out here. A heavy bike and upright posture make hills very unpleasant. Security is a huge plus for bike share, not having to think about where to lock up my bike semi-safely would be great. Seems dependent on rack coverage though, which is tricky.