I agree with most of what you said, and the design of the John Madden Center definitely could have been better. Having hardly any seating on the field facing side was a mistake (that aren't just chairs and stools on the balcony levels).
The "High School" side you are talking about is the original grandstands, built in 1935.. They keep saying they're going to do something with them, but I don't see that happening any time soon.
I love the stadium personally- My favorite place to watch football. Usually a nice temperature too.. They repainted the West Side with the boxes, and I don't like the colors they chose, but it's still a good structure:

(this was before the new paint job)
If you sit on the East Side stands (old side) near the top you get to look out toward the 2 dormant Volcanoes looking West which is really a spectacular view.
One part you forgot to show is the new "Beer Garden" they built in the North Endzone which turned out pretty nice:
It has about 3 terraced levels, with a top level where food and drinks are served.
You guys can watch the stadium in all its glory on ESPN for the home opener vs. Idaho. They will be showing the new Madden Center and stuff. Stadium should be pretty full.
Unfortunate for both our schools, construction costs continue to shoot through the roof, especially in California, which is way more expensive building than say in Texas @ UTRGV.
At least both Cal Poly and Davis haven't gotten super over-leveraged on stadium construction cost stuff and into extreme debt (like Cal did with Memorial Stadium). I am pretty sure the Madden Center isn't even completely paid for yet and they still need millions in donations as it went over-budget. It always seems to cost about 1.5X as much as you think it will these days..
I like Davis' stadium too and am pulling for you guys getting it upgraded, it has very good bones and a nice design.