In case you hadn't guessed, the 4X is Marzocchi's dedicated, top class 4X fork. The 110mm stroke uses a mix of coil and air top-up, with a much smoother compression damping set-up than Marzocchi's Dirt Jumper forks.
In other words, if you run it soft for steering traction or taking the tops off jumps it still stays soft rather than clattering into the compression damping. It does get more wooden if you increase the pressures to tackle big stuff or calm pedal bounce though.
Rebound is pretty basic too, but it's enough to keep the fork connected to the ground and out of your face when you're going flat out from gun to tape. The all-alloy structure saves masses of weight over the Dirt Jumper models (600g or nearly a pound and a half), which is a real boost on the start snap. And yet, the fork is still stiff enough to carve the berms, with a bolted 20mm axle locking the wheel in tight and true. The simple, oil-soaked internals mean reliability should be impeccable too.