I have not yet test driven the IS250 and IS350 models, but am very interested in both. I live in New England so I am leaning toward the IS250 for the AWD option, however the power and acceleration is important to me. Have any of you driven both models and how much of a difference is there between them in the feel of power behind the wheel? Futhermore, does anyone know if they will be putting out a more powerful AWD model under the "IS" prefix in 2008?

I have the IS250AWD and have gone through 1 winter in New England. I can say with confidence that you will WANT the AWD option. The 350 is way too powerful for the Northeast (and I've been told that our dealers don't get too many 350's as a result).

Of course, if you want to shell out for snow tires, you'd probably be OK. Friends with RWD BMW's tell me snow tires are a necessity, so I'd guess that the IS would be no different.