True,
i purchased the Juki F600 about a month ago and I absolutely love it. It's quiet and so easy to use. I had a bit of time with the 1/4 inch but it was in the manual....go figure.
. Anyway, I'm sorry I can't actually address thickness but you can read seem reviews searching google.
I have no regrets and think it has so many features....for the money.
Desi