The better biomes is definitely nice, and I've tried the trees mod by Dashu, which also looks great, but at least with that mod, I started to get certain vanilla textures showing in the low resolution mode, making the game look bad. I could use the gfx command to make them high resolution again, but I'd have to keep doing that as I moved around because they'd eventually be low resolution again. Things like vanilla trees and grass and vehicles would all look that way when the mod was installed. I would happily take a performance hit in order to have a way to force everything to use the high resolution textures, but when I can't force it to always use those, it just wasn't worth using in my game. I'm guessing that better biomes one would have the same effect. It seems that anything that adds enough extra textures causes the problem as I've seen the same situation with certain other mods.
As far as the second image, the ivy isn't bad, but I wouldn't want the graffiti. For one, it doesn't show the texture under it (no brick shapes under that), which makes it look odd. And second, there are only going to be a relatively small number of graffiti images and seeing the same ones hundreds of times around a large city would look bad, imo. If the game could automatically generate random graffiti that looked good and matched the underlying textures, I would be interested. Otherwise, that's one that I'll avoid.