HP Pavilion vs. HP TouchSmart laptop, which one should I get?

The dv4t will offer longer battery life thanks to the 12 cell battery. Since it would only have 3GB of RAM, there is no need to purchase Vista 64-bit, unless you plan to upgrade to 4GB in the future. However, the tx2z will be smaller and therefore lighter than the dv4t, so you have to take that into consideration. Both of them are portable, but you might enjoy the touch feature on the tx2z for taking notes. Performance should not be an issue; I have an HP laptop with an AMD processor and it runs everything well. In any case, the tx2z is a better buy because it has the touch screen, a feature not found on the dv4t. Hope this helps!