My problems are usually during the installation, not necessarily related to Arch, but more so that EFI requires its own partition. I’ll partition my disk, forget that I need a FAT32 partition and then have to destroy a partition so I can add in the EFS . The other problem I’ve had is that the bootloader entry sometimes doesn’t get written after installation, so you reboot and then nothing, so you have to boot back into the ISO, remount everything, reinstall the bootloader (in my case, Grub), and reboot again.