The sleeve gives a nice thickness and allows the stitch to "move" in a snakelike way. It's very eye-catching. A nice way to knit a pattern and hide the wrong side.
If you make this wide enough it can double as a stocking hat. The pattern is very stretchy and doesn't require edging to keep it strong. Using a good, firm worsted weight yarn on small needles also gives a sharp architecture to the pattern that is thick enough to keep ears warm on a blustry day. When you're done wearing it as a hat, a slight tug on the end slims it back down to scarf width.
For scarves this really isn't an issue, but my gauge was 5 stitches per inch in stockinette. Since the pattern expands and contracts, I'd do a swatch to make sure you have the size you need.
Started knitting when I was a child. Gave it up for child raising and work. Started again as a creative outlet that also provided my kids with warm, snuggly clothes.
Now that the kids are growing and I am learning to deal with a disability, knitting is a great creative outlet! It gives me joy on a dreary day and is really excellent therapy for my hands.