I've used the QuiltSmart. Very easy. No curved piecing to do, but you need to use an invisible applique stitch after fusing the arcs to the background square. The nice thing about this method is that you have to sew squares together (rather than piecing curves) and it lies very flat. Sewing is quick and painless.
I've also done arcs cut by accu-cut and sewn with the Curve Master Foot. COOL. very easy. NO pins needed. I'm working on one of those now. I find the trick to getting them to lie completely flat is being very fussy about the seam allowances, but the Curve Master Foot makes it really easy.
If you PM me I can give you details on getting the pieces cut using the accu-cut.