They're a little brighter and whiter... any bit more light that helps me see something in the road is worth it too me. I suppose if I drove out in the middle of nowhere at night and did a standard/Silverstar bulb comparo then I could see a BIG difference. But I did see a nice difference when I put some in my old Escort though.
I also built a headlight relay harness for the stang, the headlights get power directly from the battery, so they have more light output. It's still a far cry from HIDs... but the flash-to-pass mode is pretty friggen bright though.