I also have both, my desktop/tower runs XP Home and I use that for my graphics works, photo sharing online and my 'side job' of photographer(Weddings, etc) I keep that stored on the tower. My lap top I do everything else. It is literally my personal computer. I keep track of my tv shows, my online forums, emails, fanfics(Yes i'm a bit of a junkie with my Flashpoint and Numb3rs fanfics) and my monthly animal pictures.
My biggest problem with Vista was networking back to the XP machines. MY laptop is the only computer in our network that ran Vista. both of my brothers(Lap and Desk) tops both ahd XP, my dad's had XP and my tower.Takes a little provocation.
Comes down to it, Once I let my uncle get my laptop set well(He's a programmer and his work computer runs Vista Pro, I've got Vista Home) I haven't had a lick of problem with it. My uncle suggested to me to wait until service pack 1 comes out for Window's 7 before you buy it. Typically the 1st service pack irons things out, that's his suggestion. I think it'll be a while before I buy another new computer, I just simply can't afford them.