Was once great, now apparently problems with QM

I have been determined 15 years the proud owner of a Pullkicks and use it 3-6x a week in club training. Wear there except slightly rough surface and some algae actually not, and it is super as Pullbuoy and passable as board replacement.
For this reason, I now have some black (virtually, because as you can see no algae) ordered for the club training Pullkicks. Even when removed from the box the first Pullkick seemed very easy, so I've been gripping it and lo and behold, the material is much lighter, can be compressed easily, has a significantly smoother surface and is much more sensitive to mechanical damage than my good old Pullkick.
A huge disappointment.
When cleaning out the remaining Pullkicks me came the fourth before much harder. Out of curiosity I've measured it and found that the weight varies tidy, but there are basically two grades on the scale. With the package weighs a 115g approx, the other about 145g. Then I unpacked one of each kind of and also here: The variant approximately 95g, the other about 130g. The 15 year old way, 170g, but is also somewhat thicker.
In any case, 130g-Pullkicks similar stable / bendable as the old. The material is soft / smooth and can be a little easier / more compact. Overall, it appears to be acceptable by the durability.
The 95g version (approx 50% of the delivery) I will return. Only by passing around, my a pattern already various "scratches", transport-related small dents in the places where it abutted the other Pullkicks not recede and in some places, the uppermost layer is not fixed to the underlying associated (bubbling in the corners).
I am of the opinion that when a material value of + -0 and a retail price of about 30 to expect perfect quality really, especially in
Low-tech products and in particular as it used to be better.
Because Verschlimmbesserung and variations in quality 2 stars.