Yes, I want the blocks the correct size so that the quilt goes together nicely. Unfortunately, I'm not very good at sewing triangle pieces (think 6" Birds In The Air Blocks) so I usually do paper piecing when I have lots of points to match.
When I made a Bonnie Hunter Crayon Box quilt I was able to keep all blocks the correct size and there were no seams to match up so I did not need to square those blocks up prior to joining to other blocks and the sashing. It was perfect as it came off the machine. Usually, I don't choose patterns with that large of a block (12") and where it doesn't require that seams match. It was kind of fun to not have to fuss over it for a change.