Phaeton V10 TDI vs. A8 4.2 TDI

Hello together, I hope you don’t resent my double posting, just I’m looking for a comparison between the two cars above, and so I ask in both sub forums. As the title can already be guessed, my question revolves around the differences as well as advantages/disadvantages between Audi A8 4.2 TDI and a Phaeton V10 TDI. Both models are currently under discussion for me, both as an annual car or similar, mileage max. 30,000km. what A has you should also get in B. What interests me is the durability of both models, where there are weak points, which I should not leave out of my sight with a used one, and what might result in pros or cons for one of the two? When searching in the forums I found satisfied users for both models, so at the moment I can only fix the difference to one factor, and that is the EK. The Phaeton already exists with my introduction for around 45,000€, while the A8 moves more in the range +70,000€ with similar equipment. Are these differences purely image bound, or are there really hard facts in the technology or the susceptibility, which speak for it? I am happy about all tips and hints! Greetings, mars inhabitants