First boot your migrated install. Then to install GRUB 2 to the sdX drive's MBR (sda, sdb, etc.)
Originally Posted by alex2035
For most people that would be:
sudo grub-install /dev/sdX
This will replace the windows bootloader and the next time you boot, you'll see the grub menu first and have to select windows at the bottom of the list.
sudo grub-install /dev/sda
I think it's worth it to migrate from a reliability/stability point of view. Speed, security? maybe but it depends on how you use the OS and possibly your computer specs.