Schwalbe Mondial quality

I want to confirm whether it's me or it has happened to others.

Has anyone noticed a huge difference in durability between the good old Marathon XR's and its sucessor the Mondial?

I used my XR's up to 18.000 km without major problems. Now, my first Mondial is already 8000 km and it's almost completely smooth.

I came a across a german guy recently and he said that Schwalbe deliberately lowered the quality because the XR was too good in quality and too bad for business. My recent experience confirms this 100%.

Does anyone have the same feeling/experience?

There are actually two different Mondials, the folding and the non-folding. I have read several encouragements to purchase the folding version, since its quality is higher than the non-folding.

We've been riding the Mondials now since 18.000 kms, no problems until now, just some small cracks on the side.
Before we rode the Marathon, 10.000 kms without problem ( which is not much, but they are still in good condition).

I used the new Mondials in India Himalaya , Nepal , Sikkim last year - nowhere near as good as the old XR's! Side walls (particularly rear) showed distinct signs of wear after 1000ks. These were the non-folding type. Gone back to XR's for upcoming trip to Patagonia.

Same issue. My Mondial on back wheel was pretty much used after 5000-6000 km.