The block turned out fine, but I think I'll have to give myself a little more wiggle room when cutting out the solid corner pieces of each sub-unit. Also, I'm a press-to-the-side quilter, and I didn't see the bit about pressing all seams but the curved seams open until after I finished the block. It never occurs to me to press open... old habits die hard. And there are some tension issues that need to be addressed (a result of my two year old fiddling with the stitch tension knob).
So back to the cutting mat for me. Guess I know what I'll be doing while the little one naps this afternoon.