The Xbox One X sold 80,000 units in the UK during its first week, which puts it at pace with the first week sales of the Nintendo Switch, and the first four weeks' combined sales of the PS4 Pro, which sold 50,000 in its first week in November 2016.
Given that the Xbox One X did not launch with a new game designed to show it off at its best, these sales are impressive for a mid-generation update. By comparison, the original PS4 sold 250,000 over its launch weekend when it was first released, and the original Xbox One managed 150,000 in the same period.
The Xbox One X has been marketed much more heavily as a true high-end 4K machine than the PS4 Pro was - and with its own UHD Blu-Ray drive and the edge on 4K updates for existing games, it has a slightly better claim to that title.
The PS4 has outsold the Xbox One globally by a ratio of about 2:1 as of early this year, but both the Xbox One S and Xbox One X gave notable boosts to Microsoft's console in the UK. The gap almost certainly won't close this generation, but it may yet narrow.