If you are talking about the connection from the hose to bag… The general consensus seems to be that the ‘flow rite’ stuff has the least resistance. If you are looking for quick release fittings that is.
Here is yet another pic. I have not decided if I will use flow rite stuff or use the brass fittings that Cliff used on his system. See his ballast system is finished post for part info. The brass ones seem to have a bit more restriction but should hold up better.
You can also order your bags with larger diameter openings if flow is that much of an issue.
Chris, do you have a pic of your connection. I think I remember an old post that had one. I agree the blue fittings do have some restriction to them, but if you are using a self priming pump the little barb on the fitting allows the bags to be sucked completely dry. If you used a PVC type connection the fitting could seal against the bag before all the water was removed. At least it did when I ran a test using a blue fitting with the barbed end cut off.