Does your current hookup have the OAW3 transmitter hooked up to the USB port of your computer? (i.e. you are not using the 1/8" stereo connector on the transmitter side) If so then I think you are not using the DAC in your laptop but rather the one in the OAW3 which is advertized as "CD quality" but otherwise has no real specs that I can find.

If you want to use the DragonFly then I would break out the USB power adapter for the transmitter side and use the 1/8" stereo input for the analog. Both these cable came with the )AW3 so nothing new to buy there. I can't say whether or how much better this would be though.