Synthetic Insulation for the PNW

60g is the same as a fleece… Wont be warm enuff for the shoulder seasons by itself

eb fa igniter 100g will be 40% off friday morning at eb stores until noon

for extra win size it to fit over yr nitrous and youll have a bombproof 4 season setup for everything except deep winter

Only you know your cold weather requirements, but 60g Primaloft makes for a very underwhelming garment and I am not a fan of it. I would recommend you to instead get this: http://thru-hiker.com/kits/maxima_kit.php and a $70 Walmart sewing machine.

"I already have the Nitrous and a MH Phantom (which is probably too warm and puffy to layer with)"

Well it was about 18 degrees at my house here yesterday. So it all really depends. For contrast 20 days ago it was 74 degrees in Seattle. You have to check the forecast and dress accordingly. It is not prudent to generalize our weather here.

I use a combination of First Ascent down jacket and Phantom 32 for winter. I'm thinking of switching to the 15 just for a little more freedom on the low end for things like Rainier.

If you're using down it's much lighter than the 60oz thing you're talking about and you can bring a light shell to throw over it if it's raining.

Layer with the phantom, trust me. I've had a MHW Xenon over the Phantom in temps down to the negatives. You just need a good hat! Down is warmer, more compressible and lighter. You just need to keep it dry, hence the shell.

Personally, I find synthetics to be inferior, insulation-wise, when compared to down.

"I want to get a synthetic insulation jacket or parka for the NW, mostly for keeping warm when stopping during winter activities (snowshoeing, cross-country, etc) and for 3-season hiking, especially during spring and early summer when it is still raining here. I'm not going to be doing any long winter trips or high altitude-type mountaineering."

Given what you're not going to be doing, I'd suggest you at least take a look at the Patagucci Nano Puff Hoody Jacket. In combination with either a windshirt or WPB parka and a winter base layer, you're good down to at least 20 degrees, if not lower, depending on the individual. My personal preference for a winter base layer is a, you guessed it, Patagucci R1 Hoody. No, I have no personal connection with Patagucci. They just happen to make 2 very good pieces of gear that could work in your situation.