In our cold climate, 5w40 was simply too thick for my tastes. Cold starts the pressure would start at 70 psi or so and stay there for a very long time. I do agree that is held pressue better in hot summer weather, but even running 5w30 my pressue stayed around 25 psi when hot at idle. At speed, the 5w40 would consistently run around 60 psi, while the 5w30 / 10w30 is more like 50 psi.
Of course, all of this is on the notoriously inaccurate factory gauge, so take it with a grain of salt.
In your climate and driving, I'd be just fine with a quality 10w30 on a 5000 mile OCI. A 5w40 will also work, just be harder to find relative to the 5/10w30s (still not that bad to get) and cost more. Your choice!