3 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
ASUS UK reports 'high repair volume' on ROG Xbox Ally X; USB/button/motherboard complaints
This is about the newer ROG Xbox Ally X variant, not the 2024 ROG Ally X. ASUS UK told a Windows Central writer its repair centers were overloaded and diverted repairs overseas; anecdotal Reddit reports point to USB-port, sticky-button and motherboard issues.
What to check. For the Xbox-branded Ally X, expect slow warranty turnaround (repairs sent overseas) and a higher chance of board-level faults. Buy with a retailer that handles warranty locally, and log any fault early.
ROG Xbox Ally X unit died in sleep, refused to charge (no LED) after ~5 months
A Windows Central journalist's £800 ROG Xbox Ally X (again the Xbox variant) failed to wake from sleep and then refused to charge, with no charging LED, after about five months of light use. The charger was verified working on another device.
What to check. For the Xbox-branded Ally X, a sleep-to-dead power failure is documented, and recovery (power-button holds) failed in this case. Keep the unit charged and be ready to use warranty if it won't wake or charge.
ROG Ally X crashes/freezes/BSODs traced to drivers, heat, sleep resume and storage
An owner-facing troubleshooting guide lists the recurring crash causes for the ROG Ally X: Windows updates swapping in a generic AMD driver, BIOS issues, unstable sleep resume, heat, and storage corruption.
What to check. If the unit crashes or fails to wake, the first suspects are a Windows-update driver swap and sleep-resume bugs, not hardware. Roll back/reinstall the AMD driver and update BIOS before assuming a faulty unit.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Gaming consoles catalog, version 0.1.1, under the CC-BY-SA-4.0 license.