install from an existing system

[Ross Boylan <RossBoylan@stanfordalumni.org>]

Is the advice in
http://d-i.alioth.debian.org/manual/en.i386/apds03.html about using
debootstrap still a useful guide to installing from an existing
system?

I am considering such a maneuver with a system I initially built from
the daily builds because
a) I want to be on EVMS volumes;
b) Since my first attempt wasn't "for real" the existing version is in
a slightly unknown state;
c) my existing install has somehow gotten substantially into unstable
and I'd rather stick with testing.

Note this cross-install is from Debian, rather than a related *nix.

Thanks.
Ross Boylan