Sorry I don't know anything about the Juke, I have only worked on Nolting and HQ16. When i started quilting I was working at a quilt store and they had a Nolting Hobby quilter, then upgraded to a 16" Nolting. I really liked it especially the heavy metal table..it did not have many bells and whistles but it worked great...after I left there were many hands using it and they began to have trouble but when it was my 'baby" she work very well.
When I retired I bought a used HQ16 and have not had any major problems. The only thing is the LED lights on the handlebars have burned out and have not found out how to replace it without replacing the whole unit. I have enough light in the room so it's not a big deal for me yet.
When the thread breaks it is basically the thread..I change the cone/spool and most of the time that solves the problem. I also have to use a size 18 needle when I am quilting batiks especially if the backing is also batik.