Yeah, that was me who said GEM was ugly. Latest TOS/GEM I ever ran was Rainbow (1.4) and it sucked. I have seen later pics of GEM, but don't you need the Falcon or TT's to run it? And starting with what version of TOS came a better looking GEM? IMO - the more modern looking GEM closely resembles the olden MacOS look. Square & blocky as you had mentioned.
BTW: I've only ever owned Atari ST computers for the blink of an eye before selling. Did they have any kind of CLI to speak of? AtariDos or something similar? Workbench 1.3 is spartan too. Crippled almost, from a functional desktop point of view. No wonder Dopus was as popular as it was. If it wasn't for the CLI, 1.3 would be highly aggravating to use! lol