I have purchased least 10 Ibex items, using them since 2007.
Where do you live? Here in the coastal and western Maine mountains, I take an ultralight down jacket all year round. You must be out west? If we throw soaked shirts of any kind in the corner of the tent in the Northeast, they will NEVER dry, but start mouldering- there's too much humidity here.
I have used Ibex base and mid layers on three thru-hikes, but the base layer was torn to shreds mid way though both the longer hikes. I also found that I preferred a very thin short sleeve synthetic fabric over the lightest Ibex merino in the So. Cal desert where the wool was overpowered by the heat.
I agree that Ibex gear is good, but for the past year have been replacing worn items with Patagonia merino. The small amount of synthetic fabric that is now part of their wool line renders the garments much more durable than pure merino, which I find tears too easily. I have actually torn the lightest Ibex merino tights just putting them on after a shower, if I am not super careful. I agree that thumb slots are awesome, and have a Wool Patagonia hoodie that is teaching me to appreciate the hooded portion, as you outline.
I would have liked to see a comparison of the Ibex products you describe against similar Patagonia merino items, rather than referencing the synthetic lines but can understand your reasoning behind your choices. I have had excellent customer service from Ibex, an important consideration if you are too quick and your legs are too sticky after a shower.