One other problem with the Cisco config is that you can not see the FULL config.
Only the differences from the defaults.
I have had a number of problems where option defaults have changed from one release to another.
I is not possible to move a config from on software version to another (no new features used)
and it guaranty to work.
I can remember a problem with Apple Talk address gleaning.
It was off by default in the old software but on by default in the new.
It is not possible to see this by looking at the running config in either router.
I would like to be able to get a FULL config from a router if only for reference.