I've had the chatpad attached to my controller permanently for a long time. It's certainly quicker for sending messages or entering 25 characters to redeem a code. Doesn't get in the way of how you hold or use the controller and the extra weight is not an issue. If you can adjust between using an Xb360 controller over a PS3 controller then you can adjust to Xbox 360 controller with chatpad attached.
I had a white one as that was the only colour available for a while but I bought the black one too, plus the keys are backlit (unlike my PC keyboard).