I don't have experience with the combos that you have mentioned. But I do have experience with similar priced integrated in both the brands. Both brands offer good value for money.
NAD:
Bit warm
Relaxed and laid back sound
Rotel:
On cooler side
Brings sound stage forward
Hope this helps.
NAD:
Bit warm
Relaxed and laid back sound
Rotel:
On cooler side
Brings sound stage forward
Hope this helps.