I like the R8 over the Speed 8. The R8 has, in my opinion, more acceleration then the Speed 8 and as the handling may be the same the R8 feels much more solid then the Speed 8. You know my choice.
i just bought the R8, im happy with it, very fast. And yea there basically the same car besides the body work, same engine, same tranny assembly and stuff.
The R8 is the "better" car all around. It is more versitle and can handle more types of setups and circuits. The Speed 8 is the better of the two at Lemans and that is about it (off of the circuit it was developed for it just doesn't have the same spice). I love both but the R8 gets my vote.