I used to like merino but even that gets itchy by the end of the day. I wore it for years. Two years ago I went back to synthetic and have been happier. Favorite: Sitka ESW just fits me so darn good!
Merino wool is a game changer when it comes to western style hunting. Having the ability to run a single top for a week straight is a must when it comes to hunting. Also with the amount of hiking and sweating that I do it is nice to be able to dry out quickly.
Merino is warm and stink free for the longest of any baselayers that I wear. Two downsides are that they don't dry as fast and 100% wool isn't as durable. I really like the nylon blends.
Merino, it feels better wet or dry, smells better, I keep the base layer thin so it dries just as fast as synthetic. I tried a bunch of synthetics the mast 2 seasons as all my merino was old and full of holes, the new synthetic is definitely better then the kkder stuff, but still not comparable to Merino IMO. Ive now bought some newer merino with 25% synthetic yarns and been very happy with the hybrid approach.