Scratch it, baby!
I am 1 week into my XL4 upgrade from an original S3.
The Premier GUI was a prime concern for me. The XL4 handles the GUI elements very nicely, vast improvement over the S3's handling. The HD menus and new guide are quite excellent!
I had thought I'd take full advantage of the 30-day return option, but I'm not going back!
Hard to go wrong for the price, especially with lifetime resale value, unless you feel another itch to get the XL4 and all it's 4-tuner goodness.