in fact WE ( yes - i work for DHL - but not for DHL Express who are the transport division) are not known at all as that in the industry - but thanks for the creativity.
TNT are known as trash 'n trample, ParcelForce as Parcelfarce, Interlonk ans Interstink, Citylink as 5hittylink and UPS as Utter pile of 5hit though....
I would say that DHL Express are as if not more reliable than the other big carriers - especially when you think of the size of company, there are bound to be more anecdotal negatives - this is an $80bn company after all....