I am starting this thread so we can have a place to submit our reviews of Win 8 RP and keep things in one easy to find thread. Hope it works.
I have found few differences from Win 8 CP to Win 8 RP. During the install I was given the option of selecting a color scheme. This was a nice addition.
One difference is the loss of automatically switching from the Metro UI to the Desktop UI by adding a command in the Startup Folder. This no longer works. I set IE 10 to always open the Desktop version as I do not appreciate not having access to my add ons in the Metro IE10.
The Power Users menu (Win+X) still works well. Charms seems the same.
With Win CP, I could not create a picture password. With Win 8 RP I can.
My Shutdown, Restart and LogOff shortcuts all worked appropriately and are pinned to the Taskbar in the Desktop.
The Metro apps appear much more finished. I have set up the Calendar app (this automatically synced with my Hotmail Calendar for me)
The Weather app and Maps app worked fine right out of the box.
I was able to set up the news app to add content quite easily.
Haven't had time to check further items.