Direct sunlight in a tin box would preheat faster.

The JVM1790 takes a full half hour to reach 425 degrees. Forget even trying to get it to goto 450 degrees. I thought I had a bad JVM1790 unit. Therefore, since I work at Home Depot I pulled down their JVM1790 display. I plugged it into a 20amp 110v outlet. I let it run for 30 minutes. It barely made it to 425 degrees in 30 minutes. That's GE's dirty little secret with these units. It is an oven that will preheat and you can cook food in. They just don't tell you that you'll run your power bill up and be able to thaw your food at room temperature by the time our preheat temperature is reached.

I guess I should've known better. I was expecting high quality from a GE Profile of all things. But instead we get a glorified microwave oven. I thought the SpeedBake feature would brown the food and microwave it at the same time. Therefore the cook time would be much shorter. As a result I'd be able to cook french fries and pot pies much faster. But you must preheat the oven to be able to use and bake feature. I didn't have 20 minutes to stand around to wait/hope that the JVM1790 would get to 400 degrees.

I tested my newer model Maytag range against the JVM1790 to see which would preheat to 450 degrees faster. The JVM1790 got to 350 degrees much faster. But after 350 degrees is slowed down to such a crawl that the Maytag range blew right past it to 450 degrees. I think the JVM1790 made it to around 390 degrees in 15 minutes.

After getting the same poor preheating results from the JVM1790 at work I'm convinced this convection oven is practically useless. Unless you feel like running up your power bill while sitting around for the JVM1790 to reach its cooking temperature. Sorry about droning on so long but I was trying to reach 200 words.