Product review (5 stars): Great oven.  My wife loves it.  And I tested the temperature accuracy.
At first my wife thought the oven temperature was not pre-heating accurately or quickly enough. But when I tested it with a thermocouple on an electronic multi-meter, it turns out to be very accurate. Testing it with a simple oven thermometer doesnt give an accurate picture because the response times of those devices are much too slow.

It turns out that the oven was very accurate and in fact cycles above and below the set temperature by about 15F. I.e., the 350F temp is "held" actually by heating up to 365F, then the gas goes off, it cools to 335F, then the gas burner goes back on, and repeats this up and down. If testing with a simple oven thermometer which has a much slower response time than an electronic thermocouple, you get the average temperature. And you would normally want this to be the case for an oven thermometer.

I wrote up the above test results in case someone else, like me, was testing the time it takes to pre-heat the oven. Because of the slow response time of a standard oven thermometer, don't use it for that purpose. However, it does a good job as intended in monitoring the relatively steady state temperature in the oven. For an instant measurement, you need to use a thermocouple.

As a final note, on the initial preheat, the temperature (as read by the thermocouple) actually shot up to 390F and then proceeded to the cycling of 350F 15F as described above. I believe this is by design because when this oven's control panel says preheat is completed and put in the food, it knows you will be opening the oven momentarily to put in the food and the temperature will drop while the oven is open. This initial overshoot helps compensate for that loss.