I've seen a few people complaining that it doesn't work, and here's why:
You need 64bit os
Crysis has to be correctly installed.
The issues with, "you need Crysis 2 and patched to 1.9" is because of a registry issue. I installed Crysis 2 months ago, and have since moved it's directory, Windows no longer knows that Crysis 2 is installed, so when I run the Editor install, windows tells it "no Crysis2" so the editor says it cannot install. No worries, I put the disc in, said "custom install" selected my current crysis2 directory, and it installed in 20 seconds, and then the editor installed. No key bindings were changed, all saved games still work, and internet works fine.
The editor is awesome, I've made a parkour level! Haha, just jumping from frame to frame to box to ledge etc... open up some of the actual levels in the game, and explore. My favorite thing to do is simply jump around like a monkey.
It runs awesome, supports DX11, and the in-game mode works fine too.
I'm happy as hell! Trouble is, going between Maya and this.. my damned controls are all messed up in my head "ALT+Click" in Maya, and RIGHT click in Sandbox, ick.
NOW to figure out how to IMPORT from Maya!
Hope you guys don't have any other issues, I'm going to try to post this continually until it actually goes through! This message has been in my clipboard for a couple hours now as I keep hitting "submit"