There is a patch for grub1:
So basically you are not forced to use it. But the combination of os-prober + update-grub is much more flexible than manually changing menu.lst for other newly installed systems.
After testing, now I can say that Grub 2 seems to be as fast/slow as Grub 1. And it has also better resolution.
Booting from USB is certainly much slower than grub1 or syslinux/isolinux hybrid, otherwise it does not feel slow for me.
i've started using grub2 recently in gentoo.
it was not a big issue for my config ( one ext2 /boot partition, and the rest of the system on lvm inside of encrypted partition )
i especially like lvm support, and wider support for uuid. too bad the documentation is pretty poor atm.