Several years ago I bought a pair of Shure SE420's. While I'm pretty ok with them (lacking some bass imo) I'm considering replacing them with some higher end IEM's. The Westone 4's currently have most of my attention.
But I wonder: is the difference in sound clearly noticeable? And I know this is subjective, but let's say an untrained ear listens to the SE420's and then the Westone 4's, would one notice and prefer the latter?