The weakest link in the computer (still) are the hard disks. And now a days with Windows 7 64bits a large amount of RAM makes the use of 'disk streaming' less urgent. Therefore I plead for an on/off knob (I refer to Emulator X- by Emu) to make it possible loading the whole instrument to RAM. On; assembling the orchestra. Off; composing or arranging.
The benefit: Extended life time for the disks, less power and heat.
With best regards,