Rick, I've enjoyed your custom planes quite a bit. They are the planes I would have made if I could... but yours are much prettier =)
Problem I'm seeing, and I've heard others say the same, is that they tend to be a little odd in the flight characteristics, (Giles flight model, which I believe some of the Extras share). If I try and lomcevak, it will sit in one place and flip around. Or, basically any extreme movement on high rates has a tendency to make the plane behave a little like a cartoon plane.
Now, I mean for this to be helpful constructive criticism, because like I said I like your work.

Any ideas what kind of mods need to be done?
P-Diddy