UI looks indeed better. Uses FreeType instead of strike font. One can tune the freetype glyph contrast in the settings as well. And use any freetype font, like Hack (which is what I do use).

Works smoother because of usage of FastTable which replaces the old lists of morphs that got overkill. Actually, Pharo was fast for dealing with that massive amount of morphs. It felt slow because of the amount of stuff it did. But not intrisically slow.