I am relatively new to this community. But, I am not new to fountain pens . I have been passionate about FPs (and pens in general) since childhood.
I am sorry, if I am diverting the main subject of this forum topic.
I just wanted to make a post as a shout-out to one of the best Nib Meisters I have worked with - Deb Kinney. When I decided to customize nibs, I did a lot of research and got very good pointers from this community as far as Nib Meisters were concerned. Given the long turn around time with Mottishaw and Mike Masuyama, I decided to go with Deb. I was amazed at the work she did for me and that too in less than two weeks. The stub that she produced was silky smooth - smoother than my original nib. Ever since I have been sending her at least one customization request every month - I have had Deb customize my Pilot Custom Heritage 91, Sailor 1911, Sailor Pro Gear II, Platinum #3776, Lamy CP1 and the list goes on. I really recommend Deb's work - I guarantee that you wont be disappointed.
I have used John Mottishaw's service only once. I had purchased from nibs.com Sailor Pro Gear II. Since I had read only great reviews about John Mottishaw's work, I decided to get a simple stub on my Sailor Pro Gear II. I paid $55 for this. When the pen arrived it was horrendous to say the least - it was too scratchy and pulled on the paper (I use Moleskine and Clairefontaine notebooks). I sent it back and I was asked to pay additional fees ($45). Even after the second round and having spent close to $120 (including shipping), I still got a extremely scratchy nib. I finally sent the to Deb and she waved her magic wand and wallah! a beautifully smooth stub. I hope I did not offend any avid fans of Mottishaw. But just wanted to let the team know that just be careful when you make a customization request. May be talking to the people at nibs.com on the phone and sending a writing sample might help (I did send a writing sample with my second request but did not talk to them on the phone).
I have tried most of the pens you cited. Maybe I would have liked them if a nib craftsman had worked on them. I am surprised by your experience with nibs.com. I found their work perfect. Goes to show that YMMV. Different people have different experiences with the same vendor.