I love pressing open because everything lies flatter and it's easier for me to match up seams. When I press to one side I have trouble with getting an extra tiny fold that makes things come out slightly undersized. I also never really got the hang of the nesting thing and couldn't get my seams to match up that way. Lastly, when pressing to the side I would inevitably end up having to match up at least a few that were pressed in the same direction, for whatever reason (poor planning on my part, etc). Anyway, I finally decided to just shorten my stitch length and press open. The final result for me was well worth the extra time.