I have used various merino boxers (FL red desert, smartwool, minus 33,sitka,,etc), and like then all. However, they will eventual separate in the crotch area - the red desert goes especially quick.
But, this fall I tried out the the First Lite Dobson,which uses their aerosol blend, and these things are crazy good. The material is listed as 65% merino/35% polyester, but isn't rough and scratchy like the old core4element 50/50 blend - it's actually quite soft, like full on merino. Also, they have a very small little stretchy diamond of 100% polyester right in the crotch area where the material usually fails. I ordered my first pair in October, and have since ordered several more. The little diamond in the crotch area seems to hold up quite well. This may become my go to. ...