Exchange 2000 IS size solutions

Hi all.

I am currently looking into a product from www.kvsinc.com called Vault which will help my firm pare down the size of the IS.

It would help backup windows and access times, and looks, generally, like a good system.

However, we want to make sure we look at all players in this field. I’m looking for people with experience with this product to give me some meaningful feedback [positive and/or negative] or for feedback about other products that accomplish this same sort of thing.
My environment is Exchange 2000, Outlook 98, and OWA. We will be upgrading to Outlook XP in six or so months, but the solution should be in place before that time, so it still has to work with OL98.

I look forward to all information, thanks.