Bought to replace a competitor brand that was slow to heat up and cooking took forever. This is fast to heat up with 15 different ways to cook in the oven. We have only used three of the waways so far. No pre-heat I use for my biscuits,Air Fryer I use for chicken and fries, 
Awesome on these. Bake for everything else. If there’s anything I would change about it is the L.E.D. Touch screen is a little too sensitive and if you’re not careful you can cut the oven off .