19 mm spacing on a four string works for me, but not on a five string. I didn’t think the 19 mm spacing was gonna be a big deal but it just didn’t work for me. on another note when I spoke to Joe We discussed the build and I let it be known that I wasn’t real crazy about having to take the neck off to adjust it. I understand why they do that. He said that is all changing, and that moving forward in the near future, you will be able to adjust the rod without taking off the neck. once I got Zon dialed in, I only adjusted it twice a year in June and December. Usually just a quarter turn and it takes a couple days to take affect folly in my experience. I never liked doing that and I don’t think you should have to do that. in fact, I always hated adjusting the neck. not the adjustment itself, but the taking the neck off and putting it back on part. It felt like I was the kings jester, and if I didn’t make him laugh off withmy head, or into the dungeon very uncomfortable for me. Was always wondering if I was tightening the neck bolts too tight and eventually the threads were gonna get loose and stripped out or something and that never happened but I just didn’t like it.