They changed it so much to streamline it, reduce the 'neon'ness (that bugged me the most about the new UI), improve potential expandability, make it easier to use. Bells and whistles are nice, but if the idea is to make a simple melody having too many bells and whistles can be a detriment. Personally, I don't like the design aesthetic. Still too 'neon'y to me. 1.#'s interface had a nicer feel to it, conveyed that fantasy vibe better. Still sucked in it's own way, though, what with the server-side settings and all.