Personally, my first expericence was in the wdc hydrolic. It was completely disapointment for 4 axle sand-soil load. However It was good in 3 axle rock dumper works. Less load and short dumper lenght
In addition, scaleart hydrolic for U type is almost 4 times expensive than wdc. Yes it is real hydrolic but it is expensive.
My question is that did any body tried to produce boom ? Because simply hydrolic pump production easy and cheap. First you need pump second you need a good motor. the most expensive electric motor around 20-30 $ in ebay.com. the pump about 50 eur in ebay.de. What about boom ?