I noticed your appliqued avatar - do you machine applique? If you do, and your budget would stretch, I would get a 4.0. I think these have come down in price since they introduced the 4.2.
The reason I ask, is that the 4.0 has an auto-pivot function - when you stop sewing in the needle down position, the presser foot automatically lifts a little allowing you to pivot and then goes back down when you start sewing again. Fantastic not only for applique, but piecing too. I'll never buy another machine without this function.
Also, the 4.0 has a Sensormatic function for FMQ - the foot 'hovers' above your fabric and doesn't jump up and down like ordinary embroidery/darning feet.