I read somewhere that some people press the seams open and say that it is more accurate than nested seams. I tried it on this quilt and I don't like it. It's horrible to press, takes longer to piece the rows together, and the seams are not sharp. It's not as accurate either, IMO.
These are the first 6 blocks done for my latest design. There are 36 of these around the outside, the other 30 blocks have two rows sewn together and ready for the third. It's probably going to take another couple of evenings to do these because of the open seams. I would definately be done with them by now if I hadn't tried it.