Apple shipped 29 million iPhone Xs in Q4 2017, making it the world's best-shipping smartphone model over the holiday season.

Accoring to Canalys, the doption was driven by upgrade demand in operator-centric markets, where Apple's installed base is high and customers can finance the cost of handsets over many months. Another notable highlight for the iPhone X is that of the 29 million shipped, 7 million were in China.

"The iPhone X performance is impressive for a device priced at US$999, but it is slightly below industry expectations," said Ben Stanton, Analyst at Canalys. "Apple struggled with supply issues in early November, but achieved a massive uplift in production in late November and throughout December. This helped it meet and even exceed demand in some markets by the end of the quarter. One major benefit to Apple is that customers are increasingly realizing the residual value of their old smartphones, opting for trade-in programs to offset the high price of the iPhone X. But that big price tag, and Apple's split launch strategy, still had an impact, and shipments were not the fastest ever for an iPhone."

Apple's iPhone SE, 6s, 7 and 8 models also shipped well in Q4. The older handsets are still popular with iPhone users looking for value for money. "Apple is looking at its best performance to date, all thanks to the massive changes it made to its portfolio in Q3," said Canalys Analyst TuanAnh Nguyen. "This strategy has hedged Apple's risk as it upgrades the iPhone, in both design and user experience. While new technologies, such as Face ID and bezel-less displays, help to justify the US$999 price tag and maintain competitiveness with Samsung, Huawei and Google, having a larger portfolio allows Apple to meet its overall shipment targets, and protect its market leadership in the premium segment."