Radiant convection heaters

Many modern space heaters are mostly radiant-convection heaters, that is, they combine the two types of space heating (radiant heating and convection heating) though in proportions that vary with the models (say, 30% of radiant heating and 70% of convection heating).

See: Convection vs radiant heating

Radiant heating is personal and spot infrared heating, directed to people and objects. Radiant heaters are able to generate instantaneous heat. They heat like the sun, and we feel the warmth instantaneously, without having to wait for the entire room to heat up.
Convection heating is aimed to heat the room air. Convection heaters aren't focused on heating the people in the room or objects, directly. They heat the air and circulates the warmth through the room.

Customer reviews of radiant-convection heaters

The best customer reviews for radiant-convection heaters vary with the exact type of heater: electric or gas, ceramic, quartz, panel…

See, for customer reviews in Amazon.com:

...Ceramic space heaters: Ceramic space heaters
...Quartz/infrared space heaters: Quartz Infrared space heaters
...Oil-filled space heaters: Oil Filled Space Heaters
...Electric panel heaters: Electric Panel Heaters
...Electric baseboard heaters: Electric baseboard heaters
... Electric fan heaters: Electric Fan Heaters
...Electric wall heaters:Electric Wall Heaters
...Radiant heaters: Radiant Heaters
...Kerosene heaters: Kerosene Heaters
...Wall gas heaters: Wall Gas Space Heaters
...Small gas space heaters:Small Gas Heaters

Advantages of Radiant-Convection heaters

The ultimate goals of radiant-convection heaters is to combine the advantages of both radiant and convection heating.

They add versatility and, due to their popularity and high sales, the most typical radiant-convection space heaters (electric ceramic, electric quartz...) are inexpensive or relatively inexpensive.

Possible disadvantages of radiant-convection heaters

Radiant-convection space heaters may have higher running costs than true radiant heaters - if you just want spot and personal heating.

On the other hand, the heat they produce may not be as evenly distributed or comfortable as that of true convection heaters; and since they usually use fans, they aren't as quiet as typical convection heaters.

But all this is very relative, and varies with models and manufacturers.