I did answer your PM.
Here's what I said.
Oh yes. The sounds are much improved. Screen is full color and larger.
Lots of little things...some bigger things. The 4x plays CDG (karoake) files if you are into that. The Songbook feature is better on the 4x. The Performances have been eliminated and Setlists have taken their place, all integrated with the Songbook.
The 3X is fine, but they aren't really supporting it any longer and it won't play the great new styles that the 4X has.
Go for it! I keep trying to find another arranger that measures up to it and can't, and I've tried 'em all.
Hope this helps.
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