Different price classes - Marantz MM7025 costs roughly 4x what Yamaha R-S202 does. Expect it to lead on paper; the question is whether you will hear the difference through the speakers you own.
| Area | Better | Why |
|---|
| Power | B | Marantz MM7025 has more power - 140W against 100W into 8 ohms. That is about 1.5dB, which is a small step in loudness but real headroom on peaks. |
| Price | A | Yamaha R-S202 costs less - $250 against $1,000 at list. |
| Watts per dollar | A | Yamaha R-S202 is the cheaper watt - about $3 per watt against $7. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Yamaha R-S202 B Marantz MM7025
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. 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.