I think that both will work just fine for a OBW.
They'll both give unique looks.
If you want to get a look at what might result, try a pair of mirrors standing on end. Move the mirrors til you see 6 reflections.
No reason why you can't do a wall hanging size. Yes it will be smaller, though you will still see the kaleido effects ... and will know you want to watch for larger lengths to do a full size quilt!
There was a OBW shown on here, earlier this week, where the poster had interspersed plain fabrics, so each of the hexes showed. That'd help your sets grow into a larger piece too. All depends on what look you want.