Looking to buy a massive amp, reviews seem decent but then again anyone can post a review. Wanna know if they are any good? True to power ratings, good sound, etc...
I'd stay away from the nano's. I had the NX5 and it overheated and went into protect without an external fan on it. I believe they do rated though if you have the proper electrical and air flow.
The NX4 and NX5 appear to be overrated on the full range channels. They also tend to run hot (the full range channels are class A/B). Nothing special IMO. If you want a compact amplifier, get a Class D amplifier. If you want Class A/B, then having small heat-sink doesn't help with cooling.