Mine is a love/hate. I love the machine that is straight forward, almost no learning curve. Flip the switch and it's ready to go. Maybe 90% of my sewing is piecing quilts. The 1/4" on my mechanical machine is perfect. Feeds the fabric perfectly. But the machine it's limited in capabilities. When quilting or sewing garments, I love the Bernina.
The Bernina demands respect. It's in control and must be used according to strict requirements. Being an artist, I struggle with following the rules.
I've learned to walk into my sewing room and immediately flip the switch on the Bernina. The electronics takes a couple minutes to be ready to sew.
By moving the needle to the right, the material can be aligned with the right side of the 01 foot and the fabric still touches the feed dog on the right side. This way the fabric feeds evenly with both of the feed dog touching the fabric, I find the 1/4" foot difficult to maintain a 1/4" width seam. Since not both feed dog touch the fabric the fabric is pulled to one side and stretched crocked.
Sewing 1/4" seams is a minimal use, almost insulting for the capabilities of Bernina machines.
I think the Bernina machine is much better suited to clothing construction and embroidery than piecing quilts. The larger machines with larger harp and the fabric feed system on the top is excellent for quilting. For free motion quilting it's best to have the machine set into a table for the larger work surface. The 700 and 800 series are to large and heavy for standard sewing tables. They require the heavier tables. I'm considering the ~$500 price tag for the sew steady table. It folds up for storage and portability. My sewing room doesn't have enough space for another stationary table to put in a heavy duty Koala.