Question on 964 throttle bodies

[Slider79SC]

My question is:

Is there an advantage to the round versus the oval (1990) throttle body? I know that the oval one has a small and large throttle plate and the round ones are a single plate design.

I purchased a plastic intake (round style) that did not have the throttle body on it. I was able to swap the outer intake portions onto my existing center intake piece and everything fits perfect. I know that the center of mine is aluminum and the other is plastic but the weight savings can only be minimal at best.

So what I really need to know is if one is more efficient than the other to warrant the added purchase of the round throttle body and its pieces that go along with it?

This is for a track car and it is NOT a high dollar build power project, I just want reliable power.

Thoughts?