Its seems fairly okay, I have seen your most recent work in DF, however I still prefer ASCII over tiles as it is easier to discern what I am looking at.
At first I thought the trees and underbrush were part of the ground cover, but that is probably resultant from my partial colorblindness.
One thing which will probably never work is vehicles though 
Good luck trying to make those bastards look nice, they look distraught and ugly enough in ASCII, let alone graphical tiles.
As for the SDL version, it still runs much slower compared to the Curses version, there is a noticable lag in menus and while walking, anybody else getting this?