Whatsarunway -
The B-3 as with all previous models has only one hydraulic system with accumulators. This is - I am told - the reason why the B-3 has the same MTOW internal of 2250kgs as the B-2 - even though the external limit is higher - at 2800kgs.
The new EC130/B-4 has dual hydraulics from the AS355 and hence the higher MTOW of 2400kgs. Rumour has it that there may be an increase one day - it certainly has the performance to handle it!
The B-3 has the large tail rotor from AS355N and no strake on the tail boom as the B-2 - so is a bit more of a handful with no hydraulics.