At least one person reported a design problem with the Juki regarding ruler use. Here is a previous thread that provides quite a bit of information about the Juki longarm:
http://www.quiltingboard.com/main-f1...p-t250271.html
and you may want to check out the reviews on Amazon:
http://www.amazon.com/dp/B00CF0KMUG/...SIN=B00CF0KMUG
Edit: And one more thread from the QB:
http://www.quiltingboard.com/main-f1...m-t216193.html