For me, not having to remember at T-24 is high value, and once you add same-day standby and boarding after the A group, it's worth it to me. I fly intra-CA primarily and being able to hop on an earlier flight when my day ends earlier is a huge benefit for me. Even for only an hour flight, I appreciate being able to be handed a C boarding pass for a last minute change but still grab an aisle or window when I board after the A group.
I always make A list on segments, not miles, and I'm typically close enough to only need to add a segment or two to put me over the top (we've mastered the art of maximizing the fun of the OAK-LAS day trip on one of the first two Saturdays in December!).
This pretty much captures my experience with obtaining A-list and its value as an intra-CA flyer, as someone who also qualifies via segments. (Though I've learned the art of making a weekday OAK-LGB run in Nov/Dec...but I do like the Vegas idea!)