the speed scores the other 2 nucs not as good as on this i7-4770R Bric. Might be they i5's and this one top end i7-4770R. all are Kingston. we use a lot of Kingston memory with no issues including some ECC memory.
installed 16GB this Kingston memory in each of 3 brics and nucs; no issues of any sort; speed is great on this particular batch on this i7-4770R Bric; It in top 1% per local test.( pcpitstop )