I have the Juki 98Q and the Juki exceed f600 and love them both. The 98Q is straight stitch only, and I absolutely love it for both piecing and quilting. If there is a dealer near, I would go try both out and see which you like the best. Also, try yahoo groups and see if you can find a forum for that particular machine...there is one for the Juki 98E which is basically the 98Q....and there is one for the exceed 600....but I found more input about the exceed F600 on the Juki 98 forum and than on the forum for that machine.
I have a Pfaff tiptronic that I thought I would always use for bindings but ended up using the 98Q for that. And I have a Viking #1 which I seldom touch now.