For a flight this short, I would worry about which airport is easier to get in and out from, easier drive to/from my destination, etc.

On Horizon, they offer premium drinks and crackers, which is comparable to what they give you in F on AS IMO.

I personally, would probably take SJC, because it is easier to get in and out, traffic isn't too bad there, and I always like to see how the all new North Concourse construction is unfolding. About an year left... Almost done (they will open five gates for WN this summer, while they remodel Terminal A).

Ultimately, it is up to you, but I can assure you that there won't be any significant difference in terms of inflight service.