[pct-l] Marmot Helium Membrain?

[Nathan Dreon]

Is anyone familiar with the Marmot Helium Membrain?  If so, how do you like it?  Does the membrane make it noisy?  Do you stay dry in it when in a tent?  How about when you are not in a tent?

I'm interested in late season hiking in the Cascades and would like to be as dry as possible in my bag.  What other bags might work as well or better for this?

Thanks,
Nathan