Oh man, you're all set if you ride at Cypress. Consider yourself lucky--not many folks have access to all the wealth of alpine knowledge and equipment out in those parts.
A few things to consider about your current setup--do you know the year of your Driver X's? Burton had one year recently (I think it was 2010) where they substantially softened the boot. They didn't perform anything like they should. Your K2's should be good and stiff though.
Second, what type of angles are you riding? Sometimes it helps to set up a more aggressive forward stance than you're used to. You can push softies up to around 40 degrees, especially in front. That will give you a little alpine flavor and start getting your body used to a new position.
Lastly, although your Custom X may be a stiffer freeride board (and I'm not sure if it's stiff both lengthwise and torsionally), stiffness isn't everything. True carving boards also have a much greater effective edge. For example, at 160cm the Custom X has 125cm of edge. My 160 Donek softy carver has 139cm. It makes a big difference. Not many freeride boards will have an edge like that. Still, I've found a few and ridden them with plates and HB's, including the Prior MFR, Steepwater Steep and Arbor A Frame. They work, but the transition from edge to edge on a wide board can feel ponderous.
Good luck! And welcome to Bomber!
"''planter ben red' can be put very simply into ''the board stopped freakin fast kinda on its own''--Bomber-member Pat