Familiar with all three, I prefer the NAD and owned 2 pairs of the 370 integrated at one time. The NAD is more full bodied and has delicate highs. In my experience the Adcom has tighter but thinner bass while the rotel can become fatiguing with the wrong speakers, again based on my experience. The adcom was amp/and pre (I think 545 II or something like that) Rotel was amp only can't recall the model but had the heat sinks on the front...
The NAD is a safe bet.
The NAD is a safe bet.