LTO is extremely fast.  Generally the problem is that you either have antivirus software impacting the backup or the Exchange mailboxes are being individually backed up.  This latter case often reduces the performance significantly.

Depending on the antivirus software, you can often adjust it to ignore read access from the BackupExec agent.  The Exchange backups are harder to improve, but I would recommend only backing up individual mailboxes weekly if you can as they do take a very long time.  The full backups of the Exchange store provide a complete disaster recovery option, but the mailboxes help for individual mailbox and item restores and so are still useful.

Common practice would be to setup a full backup on the weekends (when the window is wide open) and perform nightly differentials.  I have a comment on backup I'll post a link to because you say you're a beginner on the subject -- you might find it useful.  http://www.lwcomputing.com/tips/static/backup.asp - I cover the three major types of backup and how they backup.

Ultimately, you need to figure out what needs to be backed up each night and what can be backed up periodically as well.

There really is no reason to be backup up the who drive fully every day. As long as you backup critical data and the System state you should be good. Instead of running fulls everyday just run a full once a week and then a diff or incramental nightly. This will save you tones of time. With Exchange just backup your information store as a whole. This will save you lots of time as apposed to backing up each mailbox.

Backing up and restoring to disk is going to be a lot quicker than to tape.

Hope this helps

Agreed, Brick-level backups can take for ever and are largely unnecessary.

OK great.
Thanks for the input so far.
I've been looking at the Veritas 9.1 backup exec setup and trying to understand what I can do to make it better. I do notice that each and every drive is backed up and I assume also each mailboxes.

It's difficult for me to work out for sure if it's backing up each mailbox or doing them as one big lot but I will try.
The thing with differential backups is each day a backup gets taken to a different persons home. Really we want what the person takes home to be a complete backup so we can just refer to the last person who took a backup home if required. If we used differential , it makes things much more complicated.

Is LTO the same speed as an extranl drive on a USB port?
Also I forgot to mention int he first posting that Veritas reports that final backup size as about 110GB's.

Should that be happening quicker?

LTO drives are normally attached by a SCSI LVD bus.  LTO-1 tends to be on an Ultra160 SCSI interconnect, LTO-2/3/4 tend to be on Ultra320 connections.

LTO-1 is quoted as having a throughput of around 54GB/hour, equivalent to 15MB/sec. LTO-2 is often quoted as twice this.  Often the limiting factor is other hardware such as your hard disks, memory and CPU.

External disks can be fast, but if they are attached by USB they are usually a single disk and cannot keep pace with a dedicated tape drive.  I think you'll find a significant decrease in backup speed if you use a USB hard disk.

In Backup Exec, you need to look at the individual jobs that run.  Each job is associated with a selection list.  This selection list should be reviewed.  Have a look at the section marked "Phase 3" in this link: http://seer.entsupport.symantec.com/docs/249456.htm.

The BackupExec online help is fairly good too.  The key point is that there are three Exchange backup options:

Microsoft Exchange Mailboxes --- brick-level backup of mailboxes (slow)
Microsoft Exchange Public Folders --- brick-level backup of public folders (slow)
Microsoft Information Store --- all Exchange data (fast)

Lots of valid points here. The defrag is the one that seemed to have reduced the backup window time. Another company came back in and I'm not sure if they have chaged the backup type for exchange - but I think the defrage made a big difference).
Thanks to ALL the comments which are all relevant.

Glad to help, and glad you've got things sorted :)