Here is a good example of a typical cluster. These plates have grown to a nice size and are ready to be harvested. The color is still quite strong so you know these will still be quite good for cooking and eating. Typically you can use these larger plate types for soups, stews, pizza, omelets, or any other dish that you would combine with several other ingredients. I like to save the younger and smaller blobish types for when the dish is almost exclusively made of the mushroom or even just the mushroom sautéed alone.
I have found that color and size play more of a roll in taste than shape for the most part. As the mushroom gets older it fades dramatically and the flesh will toughen and the taste will fade or become "mustier". You can also notice that the plates tend to flatten more as they age and get bigger.