After searching in vain for others' meaningful feedback on how the PC27 affects the 08-15 LC200s, I ordered and installed it last week. After a week, I can say that my 08 LC200 with 120K miles has been driving so much better overall. The throttle response is greatly improved across the spectrum, and there seems to be more power at the tap even though the RPMs don't seem to change much.
I think it's worth the $249, and it's mod money well spent. I was using City+3 for a while then Sport+1 at the moment. And so I have a few more knots of fun remaining to explore.
Give it a try. You have free 30-day insurance for buyer's remorse. The throttle changes might impress you enough to keep it. I'm keeping mine.