Different price classes - LEAK Stereo 130 costs roughly 1.8x what MISSION 778X 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 | evenly matched | Effectively the same output - 45W against 45W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases modestly (65W and 65W). |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Price | A | MISSION 778X costs less - $549 against $995 at list. |
| Watts per dollar | A | MISSION 778X is the cheaper watt - about $12 per watt against $22. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A MISSION 778X B LEAK Stereo 130
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?
MISSION 778X has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. Think about the whole system: the roughly $446 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.