I was spoilt by SGI and their wonderful interface, where every detail was awesomely cool. The Sun machines were just old-fashioned at this superficial but important level of how it all looked, but only if you knew better, and that meant experience of SGI. In the world of IRIX, we had CPU-eater desktop wallpaper, meanwhile, on Sun, you had some badly drawn window decorations.

I imagine this to be the awful GUI that you speak of.

I say look and feel is superficial, however, when you have to learn a variant of UNIX with slightly different command line switches to the UNIX you know, with an interface worse than even Windows (3.11), for it to run dog slow, a lot of copium is needed. A poor interface gets in the way of what you are trying to do, a cool interface just lets you get on with it.