I ADORE my Juki - I have exactly this model! I have quilted for over ten years, long arm quilted for the past two - and for me it is a very practical and useful machine. I rarely if ever use zig zag or decorative stitches...I'm a quilter through and through!
I haven't much issue with tension, in fact of the dozen or so machines I have I find the Juki is the easiest to tension and I can switch back and forth from various different thread weights with little adjustment. It's a wonderful machine!