For general walkaround shooting, aperture priority is often the better choice—especially if you use exposure compensation. Manual mode’s main advantages are control and consistency.

Manual is most useful when:

• The light is stable but the scene content changes a lot. Metering can be fooled by very bright or dark subjects, so manual keeps exposure from shifting unexpectedly.
• You need matching exposures across multiple frames, such as for panoramas or time-lapse.
• Automatic metering struggles, such as with fireworks or tricky reflective subjects like food glazes.

The tradeoff is that manual is slower when the light itself changes, because you must adjust settings yourself.

A practical approach is:

• Stay in aperture priority for fast-moving, changing scenes.
• Switch to manual when the lighting is consistent and you want predictable results from shot to shot.
• Take a few test frames in manual to lock in exposure, then shoot freely without the camera changing it as composition changes.

So manual isn’t inherently “better”; it’s better when you want the exposure to stay exactly where you set it, regardless of what enters the frame.