I like them both, though the 'blocky' effect bothers me, too. Upon examining the octagon quilt a bit more, I think I have a suggestion for making it a bit less blocky. The CORNERS make a difference: the ones with a prominent star draw the eye to the horizontal and vertical lines between the blocks; the 'blurry' corners merge the blocks more - like the hexagon quilts.
Edit: the octagons with light colors on the edges also draw the eye to the horizontal and vertical borders. I don't know what you can do about this, because I haven't made a OBW yet.