does what it says!
if you have old configs it can bring them forward or help do that. it can build a set of kernels (ie, if you have more than one arch). it packages them. and has some good options.
end of story it's possible with one commandline to do the round trip , copy to another host , have that host install package, and have the host reboot (maybe not on first try ok ? :)
The comparison to script shipped with kernel (circa 2012):
1) gmil works or attempts to work across...