I have sued both! The trick is to use 'metareplace' in case the entire disk goes bad!! That is faster and works okay

If only some slices are bad, then you need to follow the 'tedious' procedure that you mentioned in the very first post.

Extra:
Concerning usuing the cfgadm command, I have seen most sun engineers not using them while many sys admins use that - may be for security / satisfaction sake. Remember, cfgadm will eb used if you have scsi disks on your machine. ** 'luxadm' command is used instead of cfgadm incase your machine has fiber channel disks. (To find out if your system has FCAL disks, run format command and see if there is a long series of numbers after t (target) of the disks).

Hope that helps