One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | A | NAD M10 V3 has more power - 100W against 70W into 8 ohms. That is about 1.5dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | B | Technics SU-G700M2 Grand Class holds up better into a 4-ohm load: its output nearly doubles to 140W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | B | Both decode on board. Technics SU-G700M2 Grand Class goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | A | Only NAD M10 V3 has AirPlay 2, Roon and BluOS. |
| Room to grow | evenly matched | The same expansion options on both. |
| Headphones | depends | Only Technics SU-G700M2 Grand Class has a headphone output. Worth something if you listen late, nothing if you never do. |
| Shelf space | depends | NAD M10 V3 takes up about 71% less shelf area (606cm² against 2069cm²), and it is 202mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | NAD M10 V3 costs less - $2,499 against $2,700 at list. |
| Watts per dollar | A | NAD M10 V3 is the cheaper watt - about $25 per watt against $39. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A NAD M10 V3 B Technics SU-G700M2 Grand Class
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 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Technics SU-G700M2 Grand Class is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating.
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.