I'm in your target audience -- I used to have a wall size Thomas Brothers map of LA on my wall, and I have a large map of Southern CA geography there now. But:

Why is are most of the color schemes so garish? Did you run these by a designer? I'd think that many of the LA posters (Blackfeet, crow, Shoshone, Pawnee, even Bannock) are so garish as to be unusable in most rooms.

Why is the water the same color as the border?

And, you need deeper zoom (at least in selected areas), or I can't see what I'm getting. Within the preview, some indication of the scale of the shown features within a print of a given size would be useful.