One feature that i really enjoy is booting my system from GRUB using an ISO in the root directory of any partition on the local (USB attached, etc), or other disk.
I also enjoy this. I have started putting an additional partition on our product that has a clonezilla iso and some restoration data of the primary partition, which allows us to very easily deploy self-contained restoration procedure. A lot of our customers have been able to field repair our product this way, and since the tools are all open sourced, the cost difference was only the development hours (which are small; once the pattern is understood, it takes about 4 hours to create it from scratch).
I've always gotten this weird feeling from GRUB2 that it is just a boot-loader implementation of UEFI. I'd rather see systems get smart firmware that handles drivers etc in a sane way, and has lighter boot-loaders that get out of the way.