How does it compare with a Philips Sonicare or Oral-B electric brush?

It matches them on core features: sonic action, multiple modes, a 2-minute timer and a travel case. It skips the pressure sensor and app connectivity that premium Sonicare and Oral-B models include, and its replacement heads are less widely stocked.

Does the whitening mode actually whiten teeth?

Whitening mode changes the brushing action, not the paste. It can help lift surface stains with regular use, but it will not match a dentist's whitening treatment or strips.

How long does the battery last and how do I charge it?

The maker claims up to 30 days of use per charge, which assumes two 2-minute sessions a day. It charges on the included wireless base rather than a plug-in cable.

What comes in the box?

The handle, a wireless charging base, four DuPont ProFlex brush heads and a travel case. The four heads are described as about a year of supply.

Is it safe for sensitive gums?

Soft mode is the gentlest of the five settings and Massage mode is aimed at gums. There is no pressure sensor, so brush lightly by hand if your gums are sensitive.