Let's follow your logic.....so one has to drive a 100-series Cruiser to know that it's much faster, smoother, and quieter compared to an 80-series? That's insane with all due respect. There's so much factual information on that topic that it's common knowledge. Do you really think I need do drive a Porsche 911T FIRST before I tell folks it'll blow away an Rx8? What, I can't go by the facts? The reports?
Magazine comparo's have already selected the 4.7 over the 4.5 "overall" though by a close margin. Reports show the 5.7 blasts the 4.7 in every way. Put 2 and 2 together. It's not rocket science.
And following every diesel vehicle here on the road in the US reveals they STINK. Some are better than others for sure. Some are quieter than others for sure. NONE reach the quietness or smoothness of gas. Again, it's factual...not rocket science and that's why US automakers don't offer them. WE DON'T WANT THEM. IF you do that's OK.