The GMA that comes with my wife's ancient Atom N270 netbook is absolutely sufficient to drive Win7 Aero Glass on my Dell U2711 at 2048x1152 (maximum analog VGA output rez.) She tools around on that box all day without complaint.
Sure, the Atom processor itself is pretty gutless, but she uses the entire Office 2010 suite, Quicken, and Internet Exploder v9 without fuss. She knows that my personal laptop is 'faster', but she also doesn't know how to engage the ATI card so it just runs on the Intel HD graphics built into the Allendale i5. She only notices the speed increase when working with the RAW files from our DSLR though, which actually isn't graphics-subsystem intensive, it's all CPU work.
Both of my parents, both of my step-parents, both of my brothers-in-law, and my parents-in-law all use Intel integrated graphics on their various laptops and desktops without issue or complaint. I would know, because they call me when it IS slow
So, yeah, my anecdotal evidence > yours when it comes to REAL perceptions about video speed in day-to-day life.