For my ten penneth worth, I've owned a Berghaus 180 manual and currently have a 140ps.
I have not really noticed a difference in power - have done months away in each on the continent and both cruise beautifully at 80mph. The 140 most certainly delivers better mpg; I'd say by at least four on average.
When I changed my van, I had taken into account all the things I decided I did not want or need and focused on sustainability and running costs. 140ps for fuel economy and the dreaded EGR valve failure ( am told on a 140 single turbo it's a 'side of the road 45 min job and a 180 means 7+ hours of labour and part of the van dismantled). 16" alloys - tyres are a quarter the price of 18". Non metallic paint as it's cheaper to have work than metallic. I did add Bluetooth which has been a boon for surround sound cinema. Oh and manual transmission, find VW auto boxes horrible and have no real need to complicate things with all wheel drive. Got it stuck in plough once, disconnected traction control and it pulled straight out.
Been very happy with my choices for what it's worth and appreciate it's just my preference to save a few bob if I decide to keep it for the long haul
Dave