I use my die with two 5" squares on it the most. I am always cutting my scraps into 5" squares, and I sometimes sell sets of 5" I Spy squares.
Today I wanted to make some 'shoo fly' blocks, so I used the die that comes with the machine. I has 2.5" square and two 2.5" HSTs, plus a 4.5" square. I cut all the shoo fly HSTs and squares with that one die. I got near perfect 6.5" shoo fly blocks, so cute!
I find I have to sew a scant 1/4" seam with these accuquilt cuts, or my finished blocks will be small.