Ninja 12-in-1 Double Oven w/FlexDoor, S&D

UPDATE: BEWARE. I returned this item as I decided I did not like it. Amazon confirmed receiving it, and I was told I could expect a refund in 5-7 days. I've reached out to the seller four times and I still have no refund. Every time I reach out to them, they send me note back saying I will receive the refund in 5 to 7 days. It's probably been six weeks since I've returned the item. I don't know what to do. I would not buy from the seller. The first item they sent me was damaged and they quickly replaced it, but the second one did not meet my needs and didn't work well, and they have not refunded my money. The jury is still out on this one. I thought I would try to save money by getting a refurbished unit and purchasing the additional warranty for $30. When I received the unit, the door was on crooked and the handle was broken. I contacted the seller and I returned the unit and they sent out a new one. I've had the second one they sent out for a couple weeks now. Admittedly, I haven't used it a whole lot yet. I bought it to replace our toaster, and the first thing I noticed is that when using the top oven for toasting toast, you need to have either hot pads or Tongs to get the toast out of the very hot oven. Other toaster ovens I've had, the shelf extends out when the door is open so that you can grab the toast from on top. So that was a little disappointing. Now I have to hang tongs somewhere near the oven. I tried cooking some brownies in the bottom oven. I had to use an 8 x 8 baking dish because the others were too large. That's fine. The instructions on the brownie mix said for an 8 x 8 pan that It should take 45 to 50 minutes to cook. It took l an hour and 10 minutes. I was very surprised by this because I had read when using a convection oven that you should either turn the temperature down by 25° or shorten the cooking time. I didn't do either one, and it still took so much extra time to finish cooking. I have an oven thermometer in my full size oven. I decided to test this unit by putting the thermometer in it. I set it on 350° for 45 minutes. The instructions for this unit state to wait for it to preheat and then the timer will begin. I waited for it to preheat (it indicates when it's preheating and when it's ready.) When it indicated it was ready, I checked the thermostat. It was only 250°. It took another 8 minutes before it was up to the full 350°. I will do a little more experimenting, but I don't think that this is right. I suppose I can just keep the thermometer in there and when it gets to the desired temperature start the timer over again. I don't know if all of them are this way, or if it's because this is a refurbished unit. I may or may not end up returning it. It's awfully expensive to not be happy with it.