I already have a lightweight down jacket, so I didn't want to buy another "puffy layer." Instead of a synthetic layer, I opted for an insulated ski/board jacket. My shell doesn't have much room left anyway to layer more.
I had the chance to use the jacket in Vermont on a windy, 0(F) deg day. I wore a heavyweight base layer, then a Patagonia R1 and then this jacket, I was comfortable for most of the day. Primaloft is magic. Day 2, when it was 13(F) deg, I was a little chilly with a lighter-weight wool shirt and the R1. I have yet to experience it in warmer riding weather, but it breathes pretty well for what it is. If it's really too warm, I'll wear my shell.
The jacket itself is constructed good, I like the pockets and the fit with a longer length than I've had in the past. I think the large chest pockets on the outside will be good if I need to wear a pack. The fit is relaxed enough that I didn't have to size up, I ordered Medium and Large and kept the Medium (my normal size). The Large didn't look overly baggy, but I didn't want that much extra jacket. Biggest hood ever! It fits over my Smith helmet with room to spare (unlike my Patagonia shell).
The outer shell is softer than my 3-layer shell, which feels less constricting on top of not needing a ton of layers. The only downside of the less stiff material is that the collar doesn't stay up on its own to cover my face as well as the 3-layer shell.
This review was written in the old system and had content requirements that are different than reviews written today.