I had a Showers Pass. I now wear a jacket from MEC (Canada's REI). Save your money. The supposed breathing through the fabric is negligible compared to simply opening the pit zips. Buy for the design and cut, not for the material.
My Showers Pass does seem to hold in heat and moisture, but I'm learning to deal with it. I can't compare it with other jackets without the pit zips, because I don't have one to try currently. I trust it's good. I'm not melting in the jacket, so I think I got my money's worth. I like the cut, and I like the extreme high visibility. It also has a fabric collar on the inside, which is a huge unexpected bonus.