The HP ZBook X2 G4 leaves it in the dust, both conceptually (detachables are a superior form factor) and specs-wise; HP EliteBook 27xxp machines with similar guts are at least on par.

I'd rather have a new and smaller (10" to 13") version of the ZBook X2 G4 instead, upgrade the Dreamcolor display, keep the Wacom EMR digitzer and a sensible dedicated pro-GPU with certified drivers, and add plenty of ECC-RAM. Abracadabra, dream machine right there. Lenovo could do the same with their X12 detachable line if they had some semblance of sense.