CWM is used to perform a image (nandroid backup) of the entire internal memory and partitions and save it as a single .ZIP file onto your SDCard. This SHOULD be done after you root and before you install any custom ROMs ie. CM7. In the event a custom ROM hoses your device, you can easily restore from your .ZIP backup. Use this utility if you like to juggle/experiment with several ROMs.
I love my Galaxy Tab...just make sure you download the dolphin browser and firefox, instead of the stock browser. I have the Reefs app but I prefer to browser MR directly from the Dolphin browser. It is also great because I can use it for all of my music and navigation in the car.
It's the perfect tab for me because it fits in my suit jacket and I can carry it everywhere.