a lot of the large equipment will use a totally different hydraulic system. Yours is open center constant flow, and the pump as I mentioned earlier is teeny tiny, fully dependent on RPM since it is mechanically geared to the transmission, which is driven directly off of the engine crankshaft. The faster the rpm the more volume. At idle and low rpm there isn't enough volume to make good pressure so your loader is going to be slow and weak. Once the speed comes up it will act normally--and I put "normally" as subjective since the BX's are not "strong" by any stretch--they are mostly just lawn mowers that happen to have the same features as a bigger tractor.
On a lot of larger equipment, they use closed center systems. Then, some of those will use a variable displacement hydrualic pump. The great thing about that design is that it can make a lot of pressure AND volume at very low engine speed, which is one reason excavators only turn ~2200 RPM (max). They'll do the same work at idle speed as a smaller machine with an open center system might do at rated engine speed. Just to give you an example, of course. There are some differences among the equipment.
