@Cyber Akuma I can't speak to longevity, but we just got this, and like it so far:
The latest Wirecutter reviews rated Toshiba models very highly, and it seemed to be a good mix of power, features, and size for us. It's 1.6 cubic feet, but seems larger inside than the Kenmore it replaced. And it does have an inverter, 1200W, and a simple numeric keypad. My only slight irritation is that you have to hit "cook time" to enter a time directly -- but it has shortcuts for 1-6 minutes and +0:30, so I don't actually need to do that very often.
I ended up getting it on sale at JCPenney (of all places!) for $145 shipped.
They do have a 1.5 cu ft convection model, but I didn't consider that as my Breville already sits on top of the microwave