IMHO the most user friendly app is one that allows me a great deal of scope to customise my experience of it...

...e.g. by choosing to add plugins.

That's not to say there isn't plenty for the Poser UI developers to learn from what is implemented as third party Poser add-ons... that they could build back into the main program..

...whether those be the likes of Semidieu's various scripts, or Snarly's, or PhilC's...

e.g. Wardrobe Wizard, EZSkin, etc.

Of course, some, like Wardrobe Wizard, or D3Ds Advanced Render options, are now bundled with the app, I guess.

I don't know if there have been past examples of add-ons whose functionality has been integrated into the core program?

But still, aside from distributing the component support, investment etc... having a plugin architecture is what fosters innovation from the wider community surely...

...and that is a fantastic thing to foster... isn't it?

EDIT: X-post... in summary, I agree with what Esther said above ;)