Have long cords. They're more versatile, less limiting.
There's some science to support the claims about ionic/ions. They smooth the hair cuticle, making hair look smoother, which equals shinier, which seems healthier. Frizz is bad. (Always blow down the cuticle/shaft, not up it or all over.)
Ceramic is a very good internal material. It is heat-efficient, but does not scald the hair like metal does.
Power isn't really important. They're all powerful enough. Look for variable heat settings. Sometimes cooler is better/good enough. They might have a 'cool shot' button which blasts a temporary bit of cool air. It's a way to set the style.
What Girls & Guys Said
Opinion
1Opinion
Look for ones that:
I see i have a Vero one
Google "Wirecutter hair dryer"