We bought our Oster Air Fry Oven about 6 weeks ago.  Mostly we like it.  
However, there are a couple of negatives.
First, I've not been able to get up to the maximum temperature.  It's labeled as 230°C maximum (450°F).  I've had trouble getting up to 400°F.  
Second, the labeling on the temperature dial is all wrong.  Our unit is labeled in °C.  The numbers shown are in increments of 30° up to 210°.  So, you would expect to find 5 equally spaced dots between the numbers (each dot representing 5°C).  But no, there are 4 dots, i.e. a spacing of 6°C for each dot.  How many housewives are going to understand that?  And then there's the upper end of the dial, which goes from 210° to 230°.  Again, 4 equally spaced dots, which equate to 4°C for each dot.  The bottom line here is that you'd best get an oven thermometer and rely on it because the dial has only a passing relationship to the actual temperature.