New 12" Powerbook G4 And Cubase Sx, 12" PowerBook Performance with Cubase? Options

[Sonicom]

Has anyone done any testing of how well Cubase SX runs on the new 12" PowerBook G4 867mhz? RAM variations, Superdrive, ComboDrive, amount of tracks, Soft-synths, etc? I intend to intall the maximum amount of ram that it will take. I will probably be running an M-Audio Firewire interface with it, or maybe an Ozone controller. Any input as to how well this works prior to me making the final decision? Or should I lean toward the 15" Titanium? Portability is a factor, as is price. Thanks in advance...