Yes, it does have a seam. I suppose if you wanted a no-seam look, you could use kitchener stitch instead of a 3 needle BO, but I'm not sure how that would work with the cable.
It's not hard at all--some simple cables. You knit the two scarf parts at the same time, but could could do them one at a time. Then you cast on between them for the back of the head and just keep working straight. Three needle bind-off for the top of the head.
Finishing requires picking up a lot of stitches which needs a long circular needle, though.
I'm at the point where I'm binding off the first finishing ribbing, so I don't have too much to go.
__________________
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog