I've turned the heel of my Merino Lace Sock. It's been a really great knit so far. The pattern is simple enough to memorize, but it still keeps me thinking with the three different lace stitches.
I did notice a problem after I turned the heel. The purl stitches that were in between each lace pattern were not on the instep chart.
At first I thought this was a design element, but it bothered me that the purl stitches weren't there to set off the lace. I really like that effect. I then noticed the picture in the book, and there are definitely purl stitches on the instep.
After Googling "Merino Lace Socks" + errata, I found this post on Manning Knits. Liz wrote me and said that she had heard from Interweave Knits, and they reported that the chart was correct in the original magazine, but it had the error in the Favorite Socks book. The second printing of the book corrects this, but I noticed that the books in both LYSs I visited yesterday had this error.
If you do knit these socks, the error should be apparent to you and easy to fix. I just thought I'd point it out that you should do what you expect to do on the instep :)