Ok, 1.6.1 has been fine, I've got a few services running, it's been up 
since Jan or so, so far so good.

I'm looking at some of the bug fixes in the 1.6.2 and they sound nice 
to have.

I've read the guide to updating a working install from
<http://www.netbsd.org/Documentation/updating.html>

but I'm not sure what this "means" in terms of potential impact on the 
pkgs I've built and added to the default install from the 1.6.1 boot 
.iso for Cobalt Qubes.

What exactly gets rebuilt as part of "updating the whole userland".  
I've not really seen that defined anywhere.   It can't be all 4500+ 
pkgs from the pkgsrc tree... :)

What I should check on, should I build a tarball of /etc or *.conf or 
something before I update as a backup, or other tips on doing this with 
no disruption welcome.

Thanks,

Brian