Only a couple of weeks back, was visiting one of my daughters and she needed to replace her very old, very cheap miccrowave. we spent a happy hour looking at what was on offer in Curry's.
She wanted at least 900w, preferably flat bed, so that big oblong casserole dishes could fit in and nothing at sticking out in front - so just a quick wipe-over would keep it clean and (for her kitchen - black. She found what she wanted in Curry;s but only in white, so oad to then order the same one in black from Amazon!!!!
She does not use a micreowave much
Each person needs to decide what they need and want, obviously wattage, flat bed or turntable, I had never thought about it being totally flat on the outside as she did. Some have grills and I have never found a microwave that has a grill that was any good.
I use my microwave most days, in the winter for porridge every morning, have a couple of special microwave dishes, one does a baked apple in under five minutes, another cooks a salmon fillet in two minutes. Mine is built in above my main oven - between microwave and airfryer that big oven gets very little use. Love the flatbed ones.
My very first microwave (a great big thing) was flatbed back in the late 1970's, but they stopped making them as I was told, people were worried if they could not see what was turning around.