Just throwing in my 2cents.

1.  Graphics cards have no effect on rendering from what I understand.  They effect display, and that's all.

2. I haven't hunted around too much and I'm at work right now, but from what I've found so far testure filtering is no longer a render option in P7, it is instead controlled on a texture by texture basis in the material room.  Texture filtering really slows down a render and is not always needed depending on what you are doing or your own style.  (PS, does anyone know of a way to just shut off all texture filtering?  I hate the idea of having to go through a million textures on by one!)

3. I no longer use jpg, I only render to tiffs, but there is no technical reason that the render speed would change.  The system has no clue what you are going to save to until after you render!

Just a few thoughts.  Still, good to know about the bugs.  I'm glad I read this, because far too often if I run into a bug I figure its just me.  (Tech support on any application always treats me that way, at least and I'm more then just slightly computer literate. lol)

Hope they will resolve these issues soon.