It may be only a half pound or so, but the stock DID VL4 chain that comes on your bike is relatively heavy, and it's an "old tech" O-ring chain. A ERV4 or VM series chain is lighter and is the better X-ring chain. Not sure if the 1000DS comes with a 520 or a 525, but either way, if your looking for a little more weight loss, there's some in the chain and if you're planning on an aluminum sprocket, may as well do it.

Here's a link to the DID spec page for comparison

http://www.didchain.com/spec.html