In reply to abi:
If you are actually trekking and therefore carrying your own stuff, then don't take a soft-shell. They are great for some areas but backcountry Patagonia is not one of them - too wet.
Sure, there will be times when a soft-shell will be fine (it's often windy and a little wet) but if you actually have to make a choice of what to actually carry on your back, then you need a fully waterproof jacket and pants (lightweight is fine) and whatever fleece you want under that. For actual walking, a thick thermal is fine, with the shell over that for wetter/colder/windier conditions. A warmer layer is also needed, be it a regular fleece for between thermal and shell, or a shelled primaloft/polarguard-type garment that can go either over or under the shell.
But if you want to wear the insulating layer between the w/proof shell and the thermal, then don't get a shelled garment, as the system will not be breathable enough for walking and you will get soaked from sweat. A regular plain fleece garment is better for this mid-layer as it is quite breathable.
If you insist on wearing insulation outside the w/proof shell using a shelled primaloft-type garment(great for cold/dry mountaineering), then realise that although warm-when-wet, in a trekking situation you may not be able to dry it overnight and it will be quite unpleasant. Thermal+ w/proof shell is very versatile in these situations, with regular fleece sweater added in between for colder times. If you are not mountaineering, then changing layers is not such a hassle (no harness).
D