I did an ASR server backup and restore to install larger drives. Worked like a charm. Other than the drive size, it was the same hardware.
The newer image software allows us to change the restored partition sizes as part of the "bare metal" restore. Just pull out the old drives, put in the new ones, initialize RAID, boot the restore disk and specify the new partition sizes. The software only restores the data blocks from the image so like tape it defrags at the same time, over our network at a rate of ~1 Gb/min. Of course you want to label the old disks when you pull them out, but we haven't needed them yet.