Grub2 Slow ? in what sense are you talking about ? Easy BCD is not bootloader. It is a program that is used to configure and tweak actual bootloaders in case of bootloader conflicts. GAG is a chainloader and it requires a kernel loader to be installed in the superblock of each bootable partition to handle the different filesystems or kernels but it is difficult to install grub in superblock partition. It can be done by "sudo grub-install /dev/sdx" but i cant be sure if it will work. However in easybcd it is easy as chainloader creates a bootloader image of grub on the local drive & boots from there.
However i would recommend you to use
Auto-super-grub-disk in case of bootloader failures. Its the best choice. Install it in a PD and boot, it will show you all your installed bootlaoders and then you can choose from there.