"Long notes are longer; sharps point up and flats down." - Having notes take up more space is about the worst possible thing in the world for me; as a pit musician, the last thing I need is more wasted space on a page, giving me more page turns to deal with while I'm changing instruments and key signatures.
"...rhythms have the same spacing" - I don't know what this means. Rhythms don't have spacing. The spaces between the notes has nothing to do with the music that's played.
Then there's the fact that all current musicians would have to re-learn how to read music. Perhaps someone can tell me what's drastically broken about the current system? I'm not saying it's perfect - I don't believe any system is perfect. But it's worked pretty well for the last few hundred years.