LILO works well for me, boots my systems from md/raid1 array.
Don't know why throw it away and replace with GRUB2.
The only warts for LILO I noticed for the years are: lack of LVM/LVM2 support (especially if your LVM PVs are created on md arrays themselves), and that it searches for MBRs only on hard disks with BIOS number 0x80 and higher, so fails on BIOSes that assign removable drive numbers for your USB flash (0x2..0x7f).
For me, GRUB1 lacks a feature that I often used and liked in LILO: to create a filesystem on the entire unpartitioned volume
(like, mkfs.ext3 /dev/sdb) and then to install a bootloader into its boot sector, i.e. the case when you don't have partition table at all. Don't know if GRUB2 could do that. Anyone knows ?