can someone please explain the differences in these two systems. ive read a few thread on this topic and im trying to understand it.....is there a significant difference? does that fact that the 8 is returnless severely limit its moding potential?

 

I think this article will help you, its helped me.

http://www.autospeed.com/cms/A_2636/article.html

You can also read part 2 to see how they actually did an upgrade on a toyota.