we do mostly residential installs and i was thinking what the difference between a 3/4" and a 1" double check backflow assembly was? most all of our installs are on 5/8" meters and that is at a flow rate of about 10-12 GPM...if i remember correctly, isn't a 3/4" double check capable of about 20 or more GPM? my question is, would it make more sense to use a 3/4" instead of a 1" in this situation for these reasons: 1). cheaper 2). fits in a box easier, not as crammed as a 1" am I missing anything?