[UFO]

Swapping a DSG would be difficult, and it looks to me that the DSGs are getting significantly less economy than the 6 speeds too (but the gap is narrower than the slushboxes). I post on the mileage logs in tdiclub and all the autos get worse mileage than manuals.

If you have a specific highway speed that you drive, you can optimize your economy with a 5th gear swap, it sounds quite easy and there are a few ratios from which to choose. But if you want to go fast, you might have to get a chip tune so you can make enough power at the lower rpm of the 5th gear ratio.