Claire, they are so cozy and comfy and cushy they make the stand-up-on-its-own knitting worth it. They are a snug hug on my feet and that feels really good. I wore them until I went to bed and they do stay on my feet. I wash things before wearing them, usually, but not this time. The best part: they'll go in the washer and dryer, no special care, no blocking.
BUT - Did you see the ones jinxnit55 did? They're really lovely and that's what they're supposed to look like. I think she did the seamed version but the patterns look almost identical.
I should never overestimate my basic arithmetic skills.