I actually find the redesign quite nice. I was pretty sure I wouldn't like it when I first switched to it, I "temporarily reverted back" which helped me "map" the old functionality to the new. Stuff the blogger is ranting about are all easily "fixed" back to the old look and style, but he hasn't gone to the trouble of looking. In fact, the 2nd comment on site tells you how. The demarkation thing, I haven't used the default theme ever since additional ones were available, I see his point but just adding a background solves that. There is also new functionality for display density, i used the one which reverted to the old look.
But at least they have provided the functionality to go back to an old style look (albeit i had to dig around a bit and the average user may struggle, GMail settings are not the most user friendly IMO). I very rarely use it, but I still struggle with the ribbon style menu in MS Office, and that's been around for years!