Edelweiss, I was leery on the merino wool idea when I first heard of it. Hearing the word "wool" brought back itchy and uncomfortable memories to add to that list of the downsides you mention. You are right on the downsides. Wool is not as water repelling/wicking and they have a bit longer dry time mentioned so there are trade offs.
Hearing about folks saying how odor protected it was got me to try it and see. What I found was that it exceeded my expectations on odor protection and was soft like cotton, no itch on the Icebreaker brand I have as a base and mid layer. I can wear a shirt for a week+, sweating daily up and down the mountains and believe it or not it still smells pretty fresh and there is very little noticeable body odor after a week+. Hanging it out to dry on a branch if/when I broke a sweat and then putting it back on seems to work well. Same seems to go for the socks and merino wool synthetic blend I have. Having an extra pair on hand is all I need for week plus long trips to keep me going. I'm sold on merino wool.
+1 for me on merino wool as a good base and mid layer for insulation even with the downsides.
+1 for me on modern synthetics as well for wind protection, waterproofness and breathable layers. For me they seem to both work well together as a solution.
