As you get older, you just want to simplify your life, have less clutter and maybe have a few jack of all trade go-to items for the outdoors. For instance, take this new jacket from Helly Hansen called the H2 Flow that allegedly keeps you cool and warm when you need it. And it's super lightweight.
HH's Hollow Heat Flow (H2) system combines insulation (200g fleece in this case) with both positive and negative spaces (aka holes) and the ability to make the right kinds of adjustments to the garment to better regulate your body temperature. Put another way, heat gets trapped in air pockets in certain areas around the body and the holes in the fleece not only trap that hot air, believe it or not, but also help circulate cool air when you unzip the vents.
It sounds like bullshit marketing jargon, but I can say from personal experience that it's not. I have an HH jacket with one of the first Flow systems, and, as someone who tends to overheat pretty easily, it was the first jacket that really let me control the temperature around my body. The H2 Flow is an alternative version of the original that's been built for lightweight applications.
Here are some vids that better demonstrate the heating and cooling effects of the H2 Flow, which is available in Australia for $249.95.