I agree that the new seat selection UI isn't pretty. Wish they would run things through a design team before rolling them out, because the color scheme is a step backward from what they had before.
Heck, they could've redone the color scheme slightly and colored occupied seats the shade of blue they used before, economy the shade of blue they used before, SELECT a shade of green and STRETCH a golden hue. Nice and readable and i wouldn't look half bad either.
Besides, right now on first glance (since there are stars on SELECT and pluses on STRETCH) you'd think that SELECT might even be superior to STRETCH, when in fact it isn't..
I should take a look and see how much SELECT costs on longer-haul flights (e.g. DEN-FAI). STRETCH is $50 for those segments, so SELECT at $5 might be such a small portion of a person's ticket that they'd just buy up.
One big question I have is whether seat pitch behind SELECT will be tightened to increase passenger revenues...and increase the value of SELECT. It would be mildly entertaining to have a three-class all-economy layout in F9 birds (though they'd have to tighten pitch significantly to add another row without impacting seats closer to the front).