18-months later....
I used the gilet a lot in New York's winter Dec-March and once temperatures got to around freezing and technique of base+analogy+overlayer gilet leaves the arms too-cold and the gilet's pockets are not insulated so cool arms and cold hands. I did buy in October the Torres sleeves, thinking it would pair with the gilet.
Layering has a weight penalty of more zips, stitching, etc, but the sleeves use a yoke which I predict is neglible weight, so sleeves+gilet would be same weight as a hoodless jacket. The sleeves are so long I can keep the hands inside in lieu of non-insulated gilet pocket. So the sleeves+gilet makes a good pair, not sure if intention or fluke of my sizing.
I did in March try on in the P London store the Torres Jacket but the sleeves shorter than the separate sleeves, which I thought dumb design to have short sleeves for an insulating item.
Whilst the gilet can stuff into its own pocket, it is actually smaller to simply fold and roll it.
So, right now I have the Quito which starts around 54F at its most-vented, in the 40's closed-vents, add the Torres gilet to get me to around 30F and the sleeves then get me to around 20F.
I do also own a Down hooded jacket and I can't wear it above 25F, simply too warm, and it gets me to about 10F purely by itself and then add mid-layer for 0F.
The challenge I had last winter was just over a 48 hour period temperatures varying 20F-40F and snow/sleet/rain throughout those temperatures. The Down jacket, whilst very warm and comfortable, compressed to nil insulation around any backpack, the mid-back in particular, and so I concluded not really for walking in, but great "camp wear" and I'm looking for better synthetic multilayer solutions which don't squash-out their insulation like down. I have looked at a simple straight well-insulated hooded jacket, the PHD Kappa seems the best quality when you know it has PL1 133g torso, but when you have temperatures fluctuating so much it could be the large item being carried a lot as its too-warm.
So... my ramblings are stating I've really yet to beat the gilet+sleeves approach, its not got the insulation/weight advantags of down nor the simplicity of a synth jacket, but the flexibility wins when used in anger in winter when its fluctuating below/above freezing and rain.
The gilet is getting a lot of use now, in summer as simple insulation just over a base, somewhat baggy but just-right insulation, California having a cool damp May/June.
Right now, the Torres Gilet is my longest-owned bit of clothing, I've bought/sold most other items.