So far our restores have been in a test environment only. We are doing a
test restore of the complete system in about a months time.....

Item 1: When restoring Exchange you MUST read and understand the Microsoft
Disaster Recovery white paper for Exchange.
Item 2: Restoring Exchange using ADSM Connect Agent is no different from
restoring Exchange using any other backup agent.

A very simple process (read the white paper first!) is:
Get your documentation that reveals names, software versions etc.
Install NT (same name, same domain).
Install Exchange /R (same organisation, same site).
Upgrade all Service Packs to NT and Exchange to match the original server.
Install ADSM and Connect Agent.
Restore the Exchange databases.

The performance of the restore is about the same as a backup. The
reliability seems to be the same as any other Exchange agent restore
process.

Cheers, Chris