I like the layout, there’s quite a bit of interest, and the y arrangement doesn’t bother me- I rather like the edgness of it in contrast wth the hexies. However, if you don’t like the symetricality of having the cubes in the y arrangement you could offset the two diagonals, or do some shorter “runs” of the cubes in several different parts of the quilt. Whatever you decide to do, I think the combination of cubes and hexies is going to make a very interesting quilt.
Rob