I don't want to start a pissing contest in this thread, but looking at my YF-19 sitting here on my computer desk, I'm afraid that I'm going to have to disagree with you there. The 1/60 YF-19 is a gorgeous bird in fighter mode and I don't think Yamato could have made this anymore anime accurate without making the overall design too fragile.
I don't think that the YF-21 looks any better than the YF-19 in fighter mode, however, I feel the same way about the YF-19. I don't think that either one looks better than the other where fighter mode is concerned.
Now that, I can agree with you on. The YF-21 turned out better than even than I was hoping, I just hope that this isn't gonna be riddled with design flaws leading to a lack of durability. And I'm really hoping that this one will be QC issue-free as well.
-Kyp