I fill all stock plus a 550# sac in the port rear plus at leaset 3 people or 250# sac up front. I find that weight in the bow is really critical. When I have the bow weighted perfectly you don't even have to try the wake is so big.
Let me clarify. I fill all the factory ballasts. I add a very large sac that holds 600 in the left rear and I fill it as full as I can(~550) I also have two front sacs custom plumbed under the cushions that hold about 250 total. I fill these when I don't have people. When I do I put 3 in the front. The front does two things for the x2 in my experience. It cleans up the wake face and pushes it a little farther away from the deck(also makes the boat drive a ton better). Even if I don't have much weight in the back the front is still critical for a good but small wake on the x2. Just my experience but we have been surfing behind my boat for two full summers