WOW! Finally!

It has been a long 43-month wait for all of us, since the first LF-LC teasers and leaks were shown in December 2011. Too bad they've copied by Youxia in the meantime. Likely the new modular platform delayed it significantly. Considering that the design was frozen in the first half of 2014, I'm not sure why it took so long to see any functional prototypes testing, let alone test mules in stretched RC or chopped LS-bodies.
Let's see the differences:
I agree! The current Lexus drive trains are quite outdated compared to what the German competitors are offering.
This huge coupe needs a turbocharged 3.0L V6 as entry, a turbocharged 4.0L V8 with 400+ hp as range-toppers and a high-output 4.0L V8 with around 550hp for the F-model.
The LC500 is likely a 5.0 litre V8, but below might actually sit the upcoming 3.0 TTV6. Lexus will likely never see another 4.0 litre V8.