How does the Issa 4 Smile differ from a Philips Sonicare or Oral-B brush?

It uses a flexible silicone head rather than stiff bristles, and it is lighter and simpler. It lacks the pressure sensors, multiple modes and app support common on those rivals.

Is it good for sensitive gums?

That is its main strength. Owners with sensitive gums tend to like the soft, flexible head, though some find the cleaning less thorough.

Does it have a pressure sensor?

No. It has a single simple operation without a pressure sensor or brushing timer features found on many rival brushes.

How long does the battery last per charge?

Foreo rates it for multiple weeks of use, but some owners report shorter runs between charges than expected.

What comes in the box?

The brush and a charging cable. A travel case is not included.

Is it worth choosing over a cheaper sonic brush?

Choose it for the gentle silicone head and compact design. If you want stronger cleaning and more features, a mainstream sonic brush offers more for the same kind of outlay.