Jo, my first ever microwave was a Goldstar. I’m still using it. It’s got to be at least twenty years old. However, by this time Goldstar could be like the Maytag brand that’s been taken over by another company and no longer well built.
If you have a library card, you can access Consumer Report’s findings on microwaves/convection ovens. IMO it’s more complicated to get to than it should be, but if you call Quick Information they can guide you through the maze.