I just had this sudden fit of curiosity: do you prefer to play KS in fullscreen mode, or in window mode? Me, I find I don't have a fixed preference. It depends on the level and on my mood. Fullscreen is more immersive, and is of course the best mode for levels with a lot of detail. On the other hand, I really enjoy the "tiny little world in a box" feeling of playing in window mode, too.
I suppose you could say it depends on whether, in a given moment, I feel more like entering a level's world, or whether I want to sort of 'play god'. *g* (This doesn't mean I'm playing in god mode; when I cheat - which I do, sometimes - I generally do so by manipulating either the world file or the save file. E.g., in The Core, which was *almost*, but not quite within my capabilities, I just added one stepping block in a particularly large gap in the lava caverns. I generally prefer to keep my cheating as minimal as possible.)