A pro-merino rebuttal:Blah....I'll talk you out of it.
1. lower quality merino can be itchy, especially if wet/sweaty or you are an itchy kind of person
2. you have to baby it (versus synthetic you just wash like normal) and let it air dry (versus synthetic goes right in the dryer)
3. the anti-stink properties are good, but the anti-stink treated synthetic is excellent AND you can easily wash/dry it which stops stink also
4. it's too expensive, i can buy and have clean 3 sets of antistink synthetics for the same price (and have a clean pair every day)
5. it's not as durable as synthetics in general
6. i don't want my heat to be in my base layers, that's for comfort and moving moisture away from my body, I don't want to walk in and climb with super warm stuff on (I instead put goose down mid layers on once in the tree)
7. merino stores moisture better but synthetic wicks it better
1. I second the meriwool brand referenced already, relatively inexpensive. Likely the "cheap" brands you find itchy are merino/other wool blends
2. I haven't babies mine and it's doing great two seasons in. Yes you don't dry it, but hang it over the shower curtain bar or on a hanger overnight and it's dry the next day.
3. Seems like a wash (see what I did there )
4. Not my experience, particularly buying meriwool on sale. I wouldn't go super cheap-sometimes what is advertised as merino is a blend (see #1)
5. I haven't really considered durability for underlayers so far. That said, haven't work them out at all from what I can tell. My smartwool top has a few holes from a damn mouse, but that's a different issue.
6. Agreed, sometimes I hike/climb without it and add the base layer when in the tree
7. I seem to sweat a bit more than average, even if I get real sweety hiking around in it, I've been warmer in sweet drenched merino than I was in same conditions in sweet drenched cotton. Not a ton of synthetic experience to counterpoint this one. The super winter mountaineer types usually reccomend synthetic under merino double base layer for extreme colds I think.
8. I am 6'2, 200-220 lbs, and find the large meriwool sizes to be a good fit, not too tight, but also not loose. The tall sizes are real tall, I made the mistake of ordering bottoms for one of my 200g sets in LT, still use them but there's definitely too much leg there (generally I wear a 34 inseam pant). Also fan of darn tough socks. Particularly the hikers. Wool blends vary throughout their lineup