They're both very nice-- block one is more subtle than the 2nd because there is less contrast between the two pinwheels.
I personally like the extra contrast in the 2nd block since it allows the two pinwheels to stand apart from each other giving the block a more graphic style. I also like the way you alternated the darker and lighter fabrics in the octagon border around the pinwheels on the 2nd block.
Rob