I just (3 months ago) set up a 10i7 with 32Gb RAM, 256 Gb M.2 (System SSD) with a 4Tb SSD for content. Runs like magic on ROCK.
The NUC 11 currently isn’t supported due to limitations in ROCK. (a new version is “Coming Soon” but has been for a while)
Depending on how much you add to your library from Tidal and if you will Rip CD’s in the future I would go for 10i7, 256 M.2 (you can’t get smaller really) 8 Gb (maybe 16Gb as memory is cheap and you can never have too much hence my 32) but get the high NUC so you can add a drive later if you wish . (There are 2 shapes of NUC with or without the space to add a drive)
What does the OP have circa 250,000 tracks, with huge levels of DSP and multiple endpoints, to be listing a NUC10i7 with 32GB as a ROCK server?
Great than 250k tracks is the only scenario where 32GB RAM in a NUC running ROCK is required. An i7 on NUC10 is a hexacore processor, so 6 cores supporting 12 threads. Even with a Core per endpoint, so to utilize this CPU fully, it at least 6 endpoints playing different tracks simultaneously.
The performance factor for ROCK is single CPU thread performance, so having a multi-Core machine makes no difference.
If the OP only has a moderate library, a NUC10i3 with 8GB and NVMe SSD (you can only get upwards of 256GB devices now) would perform very well (2-core/4-threads).
Alternatively a NUC10i5 which is a quad-core (8-threads) machine with the same single thread performance of a NUC7i7DN (the board used in the Nucleus+) and give it 16GB and a NVMe SSD and more than enough performance headroom.
Of course, to get the additional power in the NUC8 and NUC10 lines, Intel had to up the TPW used by the CPU, which is not ideal for a 24/7 headless server, where the lowest TPW is better.
I have a NUC7i7DN (quad-core Gen8 CPU with 15W TPW) and the only time it consumes more than the idle power, is on initial import analysis. During playback to an endpoint, it is just idling on less than 15W.
However, my 95K track library was never an issue for my previous NUC5i3 based ROCK server, used since the launch of ROCK, and was tested with full DSP on 4 simulataneous endpoints (upsampling, downsamping, EQ filters and DSD upconverting) without issue.
Sometimes more is not always better.
The database needs are the same for local content or streaming content. So, if you are only using Tidal then you are limited to the max 10,000 album cap that Tidal imposes on libraries, aka ~100,000 tracks.
In that case, I would go with an i5. That would give you growth room in case you decided to Qobuz. I would also go for 16 GB RAM. Again, some growth room.
So the lowest spec NUC, the NUC5i3 I had running from 2017 to recently with a 90K library, had a single thread performance of 1,241
A RevB Nucleus (which I understand uses a NUC7i3 board) has a single thread performance of 1,391.
A RevB Nucleus Plus uses a NUC7i7DN board, with the quad-core Gen8 CPU with a single thread performance of 2,156. However, if you don’t need the multi-endpoint support then a NUC7i7BN gives 2,261 but Intel is working that CPU harder at 28W TPW to get that power out.
A NUC10i3 gives 2,265 circa the same as the Nucleus Plus for single thread but just a dual core for the same overall power as NUC7i7BN
A NUC10i5 gives 2,231 also in the same ballpark, but the same overall power as a Nucleus Plus with quad cores
A NUC10i7 gives 2,457 which is not much more than the i3 or i5 on the important single-thread performance but the 6-cores give it overall performance potential if the OS can leverage 6 cores/12 threads in parallel, or the workload requires it.
As a comparison, a NUC8i7 gives 2,575 but at the 28W TPW.