On the new MH4900, the ground speed is not higher than the MH8000, however, it has been increased for an entry level hydro model. The biggest difference is in the new hydro-static drive system. This new technology allows for more power to the track system. Previous models had 1,500 PSI going to each track..now there is 3,000 PSI going to each track on the MH4900.
You are correct, the MH4900 has a dedicated 10 GPM going to the attachment valve. The PSI is regulated on each section for our specific attachments, but the valve also allows full 10 Gpm flow to the PTO or mini-skid steer connection. On the MH8000 the hydraulic system works a bit different. The HC74 hydraulic circuit allows the track and aux. pumps combine flow to the attachments. Total flow would be 23.5 gpm. When looking for speed hitch attachments, stay in the 10-20 GPM range.