I've tried it, but it seems opinions and results are varied.
Some have slower speeds with new modem, some have better, for me, I don't see much difference, IF at all. I am still testing though.
Only thing I am testing with is speedtest.net app. I am testing in different areas, as my job I am different places at different times, so reults can vary, and I have down tim at spots so I can swap out modems to really test both at the same area.
As for the kernel I'm not sure what has changed. I didn't see any "noticable" change or anything different per say.