Tosh Merino Light: (the Tosh Sock is too heavy for my taste so I bought this lighter yarn) This is expensive stuff, quite like Malabrigo sock. It's a bit more "thick/thin" and not as uniformly spun, but tight like the Malabrigo. There is no nylon; it's 100% merino. It knits up very nicely and has lots of body. The colourways are spectactular, no pooling or striping, very deep and complex. Because the yarn has no nylon, you really should knit in nylon reinforcement thread, or use a different yarn (with nylon in it) for the heels and toes. You will be darning in short order, if you don't. Believe me. I've learned!! The same goes, btw, for socks knit in Malabrigo sock.
The yarn gets softer with washing. It does felt a bit (especially inside the foot), and I find that you get colour changes ("bleaching") on high-abrasion areas (ex. ball of foot) within a few weeks of wear. Because of the colours, it doesn't show patterns well, but simple, rib-based designs look very nice. The vanilla bean colourway I picked is actually very manly - much less violet in it than some online pix might suggest - and D.H. likes the socks! This, along with Malabrigo Sock, is now one of my favourite high-end yarns. In fact I like the Tosh "solid" colourways better for the gents in the family since there's so much selection in green/brown/black colours.
[tosh merino light; vanilla bean]
Sweatermaker Simply Sock: a friend picked some of this up at a thrift shop, and I'm knitting her up a pair of socks. I do not like this yarn. Perhaps it is a "second", or the fiber-artist's first try, or something, but this yarn has one amateurish dye job. It is heavily overdyed and bleeds onto my fingers as I knit and will give my friend blue toes. It is clearly dip-dyed in a single colour (blue), and so it is pooling/striping. I mean, I've done better with my own home-dye attempts! I'm sure that once the dye is fixed (I'll wash the finished socks in some vinegar and/or salt) they'll wear fine, as the yarn is pretty generic superwash, machine-spun, with nylon.
[sweatermaker simply sock]