Both are NAD, from different ranges - the engineering approach is shared and the differences are mostly in power, connectivity and price.
| Area | Better | Why |
|---|
| Power | A | NAD M10 V3 has more power - 100W against 80W into 8 ohms. That is about 1dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output barely increases (100W and 80W). |
| Noise floor | B | NAD C 368 BluOS-2i is the quieter design on paper - 98dB against 90dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only NAD M10 V3 handles MQA. |
| Streaming | evenly matched | The same streaming platforms and services on both. |
| Room to grow | evenly matched | The same expansion options on both. |
| Headphones | depends | Only NAD C 368 BluOS-2i has a headphone output. Worth something if you listen late, nothing if you never do. |
| Shelf space | depends | NAD M10 V3 takes up about 67% less shelf area (606cm² against 1840cm²), and it is 145mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | NAD C 368 BluOS-2i costs less - $1,749 against $2,499 at list. |
A NAD M10 V3 B NAD C 368 BluOS-2i
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both amplifiers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
NAD M10 V3 is ahead, but on only 1 of the measured areas, and it costs about 43% more. That is a lot of money for a narrow margin - NAD C 368 BluOS-2i is the sensible buy unless a specific feature above decides it for you. Think about the whole system: the roughly $750 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
What a spec sheet cannot show: how either sounds with your speakers, how the controls feel day to day, and what the app is like to live with - which is where most all-in-one amplifiers are actually won or lost. Power figures are the manufacturers' own and are not measured to a common standard, so treat small differences as noise. If you can hear both, that will tell you more than any row above.