Let me share my first impressions with NUC8i5BEH2 config (250GB Samsung EVO Plus NVMe M.2 SSD, 1 pcs 8GB 2400 MHz CL17 Apacer RAM module).
It was easier than expected to install ROCK and migrate the existing Roon database. The NUC runs relatively quiet, but I will go fanless once my Akasa Turing case will arrive (expected around mid January)
Power consumption and performance:
As I mentioned earlier this was my biggest concern. But now I’m OK 
When in idle, the NUC consume not more than 4-5 Wh, and under load with the used DSP settings it goes up just to 6-7 Wh. OK, I do not use CPU intensive DSD conversions. Slowest processing speed was 9x with a DSD file, but generally it runs around 18x, which means I still have enough computing reserves…
Sound quality:
Well… someone says bits are bits. But based on my experience it’s not fully true. (Do not deny anything before trying, this is my philosophy.) Running ROCK on a dedicated server gives me more balanced sound, better sound stage, more details. I’m satisfied with the change… All in all it was a good decision to invest in a NUC.