lenny with new installer

[Ross Boylan <ross@biostat.ucsf.edu>]

I am testing upgrades from lenny to squeeze in a VM.  To get as close as
possible to my existing system I used the lenny installer, but the new
installer reportedly supports lenny too.  If I use it, will I get the
same setup in the end?  In particular, I need software RAID with the
same metadata format (0.9) than I'm using for real; I also have LVM and
dm-crypt.

My concern is that the newer installer will use newer versions of tools,
especially for some of the initial low-level setup.

If it is safe to use the new one, how does one get lenny?  Some docs
suggest it's an option in expert mode.

Thanks.
Ross