Personally, I'd connect in LAX. Since OP is going from LAS to SFO, both flights are likely to be in terminal 4 in my experience, so less of a shuffle than the PHX airport which is much larger. An hour, assuming OP is in front of the plane, will allow him to get off SFO-LAX, head up to the AC for a drink, catch a good view of an international runway, and make the SFO connection. In the event of a misconnect, there are lots of SFO options.

PHX is less likely to have weather problems. I like it but its more industrial to me than LAX.

As an aside, on a pure domestic flight without an international connection, does OP get free access to the AC? I thought you needed an international connection.