Why do you think it's a better system? Interested to understand the pros and cons a bit more. thanks (sorry OP did not mean to threadjack).
I've had both for years, I've got a good 60-70 days of hard riding on a 2011 Burton with EST/ICS. I just recently bought a non-Burton board again as my primary board and was reminded of how limited you are with the 4x4 system. If you want any adjustment towards the heel edge or toe edge, you're stuck with whatever stance widths the board comes in and vise versa.
I'm picky enough that a 1/2" here or there makes a difference to me, and having essentially infinite adjustability inside that window makes a big difference.
Some people talk about the flex pattern of the board being different (ie. better with EST than without) but I didn't notice any difference that way and I have identical bindings on my EST and non-EST boards. So I guess the short answer for me is adjustability