The cloth map is just that - a cloth map (if you've seen a Tolkien map, you'll know what it looks like), with icons representing cities and resources (they are quite pretty) and little models representing units. The game is totally playable like that, but it is harder to appreciate exactly what you are looking at, at least at first. The cloth map is normally only used when you zoom out loads, but you can set it to be on all the time.
On performance: Ocasionally even my desktop beast (i7 920, HD5870, 9GB RAM), will slow to a crawl later in the game. I have hopes that the patches will fix this, as lets be honest, this game really shouldn't be as demanding as Crysis maxed out.
