If you can, take pictures of your layouts.
For some reason - which I don't know - it seems like one "sees" things differently when looking at a picture than looking at the real thing.
The no-sashing layout makes me think of the very old-fashioned crazy quilts.
The sashing separates the blocks and lets one see that there are individual blocks. Then the "game" is to try to identify the similar placements of the pieces.
Both look nice to me.