I haven't even owned it that long but already it has saved me a load of money on batteries.
At first, you will notice a very slight change in weight of your controller, but you soon get used it.
The lead is very long and fits snuggly on to of the controller; you will hardly notice it when you play. It's easy to attach; so rather than panicking, trying to find new batteries, you can easily plug it in and continue to play. Worth every penny.
And of course, I bought it in black - Didn't want to look a fool now; you spend so much on an Elite console, might as well finish it off for just £2.