Any idea where the new Primaloft Thermoplume sits compared to the Silver/Gold insulation? The press bumph is saying the best ever etc etc etc but appears to sit in the Black range which is below Silver/Gold.
You can’t look at the insulation value of the filling itself in isolation. Lots depends on construction as well – the downside of lightweight down is that mostly the construction is stitch through seams, so every line of stitches you can see reduces insulation, because there’s no fill trapped there, and decreases windproofing because stitch holes let wind through.
It’s why microbaffled down jackets are less warm than ones using fewer down compartments of a similar spec and explains why stuff like the MHW Ghost Whisperer and the Rab Micro aren’t particularly warm. And then there’s the fabric, lighter fabrics allow more loft and more warmth. And down density, if it compresses too easily it loses effectiveness etc.
Anyway, all of which is a round-about way of getting to the point that conventional synthetic fills score some plus points by not needing to use down-type baffled compartments, whereas down-like stuff like Thermoplume acts like down and needs more stitching.
TNF Thermoball is particularly bad because as per the name, the balls of insulation roll around, so it needs loads of quilted stitching to hold it in place, so while the fill may be equivalent to reasonable down, the actual garment has so many stitches, that efficiency is significantly reduced. Oh, and the Patagonia Nanopuff kit is effectively ‘inside out’ for fashion reasons – the brick quilting on the outside actually loses heat…
None of which matters much if you just want a warm-ish jacket, but is a bit more significant if you’re on a quest to find something that’ll work really well relative to its weight and bulk for mountain use. Sorry, blah, I’ll shut up now.