I just recieved my m15 r2 yesterday, and have had some time tinkering around with it. first of all; I have to say that I'm really dissapointed with the internal layout of the laptop. I always repaste a new laptop, so I tried doing the same here. Not only is the motherboard cumbesome to flip, half of the screws connectring the heatsink to the board were stripped and impossible to remove, therefore no repaste.
As for thermals and noise, they're not too bad. I have the 2060 and 9750 model with an oled screen. I've set the gpu to run at 1710 at 0,775v in msi afterburner voltage curve editor and verified with gpu-z. I undervolted the cpu to -140mv cache and 210mv core in throttlestop, verified with hardware monitor. I run the computer in silent mode and high power from the alienware command centre, and i got around 70C (max 72) on gpu and 80C (max 91) on cpu playing the witcher 3 high settings at 4k.
as for sound and display, they're both good, the sound only being good after loading in alienware command centre and setting the speakers to use the "alienware" setting. default setting for the speakers were too tinny and had no bass. The screen is extremely good.
keyboard and trackpad are both very nice to use. keyboard has clear actuation and key travel is nice and deep. the trackpad is glass and feels nice to type on. downloading 3dmark (free version) as I type this, will post results soon.