Virtual PC 2007 as primary working environment a good idea? What about performance, stability and flexibility?

I am an consultant working for multiple customers at various locations. I have a laptop (Intel Core 2 Duo @ 2 GHz, with 2 GB of RAM) and running XP Professional SP2.
For each customer I can create a network profile with a tool like Multi network manager and use the same XP installation for everyone. The bad thing is that it i difficult to keep XP clean that way (software etcetera).
The other possibility is instaling Virtual PC and creating a virtual OS for each client.
The host OS can stay slim (I will not use this other than for booting and launching Virtual PC)
My questions are:
- Is the performance good enough to work with Office 2007 within V PC?
- Is it stable enough (I can't affort loosing work)?
- Is it flexible enough (e.g. easy to get access to network of customer)?
- Tips to make host as slim as possible (e.g. no virus scanner?)

For your information: I'm running Virtual PC now with two virtual machines (both XP) open and I'm using 1,34 GB.