I've been writing a lot about how Max's proposal to tax benefits would work for a reason: misinformation and confusion ran rampant in the 1993 health care debate. That ended up doing a lot of harm -- not just to progressives, but to the American people who remain stuck in the most broken health care system of any in the industrialized world.
That said, even though Max Baucus's proposal isn't akin to John McCain's, there are good reasons it has a lot of people upset (I should note here that tax deductibility is not one of the areas I've given a ton of thought to in this realm).