Dear All at HPG,
Like many of you, I am dusting off the mid-layers as the Fall rolls in. Also, like many of you, my go-to has been the Arcteryx Atom LT. I now have a Gen 1 and a Gen 2; not using the Gen 1 off-duty because its issued and stands out due to the colour. The Gen 2 is inferior. Its still as warm but, the construction is not as good. The face fabric seems brittle and its not as fitted. Noisy in the cold.
I recently came across the Arcteryx Proton line. The FL (fast and light) weighs 25g less but seems warmer. The interior is soft and breathable. The exterior is soft and sheds water well. I now have the Proton Lt as well (there is a discount place near me that is 40-60% off last years models and I keep my eye on the Outlet). A bit lighter in weight to the Atom Lt but softer, warmer and fits better (5'9", 165lbs).
Can't say enough good stuff about the Proton line; warmer, better breathability (if that's the right word) and seems better quality.
When you have to pump out big bucks for this kind of gear, you want the best. I will be retiring my Gen 2 Atom Lt permanently now.
Hope this helps anyone looking around for a new and improved mid-layer.