You could lose 80g per rim by going to Stans 340s, and while DA hubs are good quality, they are not the lightest hubs. You could get a set of wheels that are half a pound lighter without using unreliable weight weenie hubs.

Whether that makes a difference is another question. My take is that unless you are racing and your races have a lot of climbing, it's not worth getting all obsessive over. A rough estimate is that losing a pound is worth about 8 seconds per 1000 feet climbed (average 7% grade, body weight 140lbs). For non race riding you can go just a tiny bit harder and gain more than that.