I think in a survey of the history of philosophy, Berkeley is one of the best examples of an Idealist. Whereas, for Plátōn, the world of matter that traps souls in cages in not made of mind.
It's a constant stuggle to decide how much diving into the details is sufficient. However it seems pretty clear to me that the ultimate goal is being sure that we have a grasp of the "big picture" regardless of the twists and turns of how some of these philosophers seek to distinguish themselves individually. Everyone seems to want to make a name for themselves with new jargon, but I see very little in the end that makes any real difference.
At the moment i am hard-pressed to come up with a better high-level way of expressing it beyond what Nietzsche was apparently doing with his "true world" figure of speech (such as in Twilight of the Idols). No matter how you slice it between mind or matter or any other single word, it seems like the issue always comes back to whether we are going to choose to live and die by the senses in this world, or by something we think we can identify only in our minds in another world.
Eikadistes if you come up with equal or superior ways of summarizing these issues please be sure to highlight them. I know a lot of people get frustated and simply pass over discussion of the details, and that's probably OK - just so they have an outline/higher-level understanding of the real dividing lines.
In the case of most if not all of these philosophers who are variants of Platonism or any form of idealism, I'm not sure that it's necessary to know much more than their orientation toward the relative value and roles of the senses vs the mind - at least that's the way I see it at the moment.