Hello,
It appears that you have quite a good solution now, similar to ours, 
backup of Lotus notes is always a problem at file level since you end up 
getting FULL backup most of the time, with all the dB compacting, 
replication and notes activity your backup times are not bad atall, i have 
continious battle with this notes servers so the only addtional tuning 
that i can think of if you do not use notes module, is to either use disk 
backup or move the notes data to the san to realise improvments, also, you 
may want to talk to notes admin so that they can fine tune the notes 
servers not to do all the compacting etc during backup hrs.
One other thing, not sure if addtional NIC in a large team is the way to 
go, you may get better network performance if you have may be couple of 
NIC teams vs one large one.
HTH

To sign off this list, send email to listserv AT listserv.temple DOT edu and 
type "signoff networker" in the body of the email. Please write to 
networker-request AT listserv.temple DOT edu if you have any problems with this 
list. You can access the archives at 
http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER