I'd agree with the temps going lower on HG stuff. I use Incubators too, so I don't know if I'd quite be the same with a 3/4 UQ.
My buddy doubles up his two 2/3 UQs. The problem is again with compressing the second UQ with the first. If you offset them, like he did, then you only get the 40* coverage down to where the next one starts, then it's doubled up, until the legs. The other thing we noticed was that there was a slight gap where the one layed on top of the other. Think of 2 books, one just covering the spine of the next one. He decided to just use one of my Incubators for the next trip.
If you have some other way to keep your feet warm, then you could probably put one 40* directly over the top of the other (loosening the tension on the outside one, so that it doesn't compress the loft of the first one) and get down to 0*.
If you're not weight conscious, then just get a 0* Incubator for year round. Vent it a little in hotter weather.
Ultimately, with HGs sale for the next day, you couldn't go wrong with just getting two Incubator 0*s! Quite a deal for a top notch UQ!
Last edited by Boomer; 11-23-2012 at 15:21..