I really like it with the sashing.

Definitely the sashing! I think it sets it off. Otherwise it's too plain.

I like them both.. either way will be beautiful. I think I would go no sashing

I like your fabric choices. Without black sashing the white background creates a secondary design good for additional quilting creativity. To increase space between the colorful areas you might consider white sashing as previously noted, and perhaps a narrow black inner border or flange with a white outer border to frame the whole piece. Looking good.

I was going to say no sashing until I saw the second pic. Yes to sashing!

I like it with the sashing.

Both!!! Do you want it bigger, the blocks to pop, or is the size just right?

I am wondering if sewing the blocks together without sashing would be problematic getting all those points to match. You have good 1/4 inch seams on all the blocks but it still would be hard to make sure it looked ok. A narrow white sashing between would solve that problem if you didn't want to use black.

I love it with NO sashing! The colors seem to stand out more, and the white background make it look floating. I would add a dark border.
Beautiful, thanks for sharing.
God bless you.

I like it both ways but w/o seems to be my favorite.