As to your original question, I'm using a 5-year old Tablet PC which came with XP and I upgraded to Vista -- and the performance, usability, and reliability improvements with Seven have been amazing!
I should mention that I upgraded the memory from 512MB (with XP) to 2GB (for Vista) -- and that got me some decent realtime performance out of it. With 512MB, it was so slow as to be unusable.
But, everything works (and that's saying a lot on this box) with Seven, even the XP-era
drivers loaded in compatibility mode.
So, I would heartily recommend upgrading to Seven for your laptop.