XP Home or Pro for Dual Boot?

I have recently purchased a Lenovo X61 notebook with Windows Vista Business pre-installed - the user of the computer now tells me that it is slower than her previous X40 with XP Pro.

Looking at past Internet comments on the differences between XP Home and Pro and having used both for the last 4 years I am in a dilemma on which to use in a dual boot.

I have successfully configured a dual boot on a $379.99 wireless notebook, Windows Vista Home Basic and WindowsXP Pro. My IBM user observes that the sub $400 Sempron machine is in fact faster than her new X61 - especially when booted into WinXP.

I can downgrade the X61 for free with an XP recovery set from Lenovo, machines supplied with Vista Business and Ultimate have "downgrade rights" until sometime in 2008. However, I would like to configure a dual boot on this computer so that the user can experience the inevitable use of Vista sometime down the line.

My question is: I have seen little difference in the performance of XP Home and Pro and the research supports this observation. I am aware of the differences as stated by MS and other sources. I am interested in this communities opinion.

Martin