Simon, the MDP is Dual Link, not single Link. In fact, all Apple Devices with a Mini Display Port (including Thunderbolt) are Dual link.
MBPs do work with Matrox devices just fine. I have teams running DH2G and TH2G on MBPs all the time for wide screen Keynotes we route to Spyder.
This is still agreed.
Not true. The Mac Mini's have dual channel SATA, have dedicated PCI bridge, and with the addition of the discrete Video, have higher video performance.
MPBs have better performance than Minis. However, it's agreed their performance is still not substantial enough where they would reliably replace a Mac Pro Media server.