Faith. And a new faith.

My faith is still crisis-y regarding preamps.

Maybe the whole theory that the accumulation of subtleties in multitrack recordings is what makes the very small differences in preamps important is actually correct.

I'm tempted to test this in a way that has one scientific flaw. But just you watch. I'm gonna do it anyway.

If you run a microphone into more than one preamp at the same time, you're loading down that microphone and it doesn't behave the way it ought to. So that's why preamp tests on the Interwebs are always one microphone:one preamp.
But uh. Modern preamps are made to bridge. And when one actually runs the numbers, the loss and weirdness of running a normal modern microphone into multiple preamps actually ain't that much. So I am going with the notion that one can record to more than one preamp simultaneously. There is a science-loss here because there is a mathematical difference. But it's worth trying because until we get robots who will exactly replicate all moves on all instruments, it's all we've got.*

1. Install and register Samplitude, Sibelius, and the most recent version of ReWire (the one that comes on the Sibelius CD is fine)
2. Start up Sibelius on its own, go to the Play > Playback Devices dialog, select Audio Engine Options and, if the "Repair" button in the resulting dialog is enabled, click it[Drew's note: I believe this option has been moved to another place in the latest version of Sibelius.]
3. Shut down Sibelius
4. Start up Samplitude
5. On the VST/DirectX/ReWire page of the Options > System dialog (which is inside the Effects group of pages), tick the box that says "Activate ReWire"
6. Restart Samplitude
7. Open a Samplitude project, and create/select a MIDI track
8. With the MIDI track selected, go to the MIDI panel (by default this is on the left of the screen, under the Track Editor); from the "Out:" drop-down menu, select New Instrument > Rewire > Sibelius
7. Sibelius should now start up (and Samplitude will give a warning message if you're not using ASIO)
8. Open your desired score; if you're using Sibelius Sounds Essentials you'll probably want to leave it a while for Sibelius to load all the required sounds. Now starting playback in Samplitude should also start it in Sibelius.
9. If you want to record Sibelius' output onto a track in Samplitude, choose a stereo Audio track, and, in the "In:" drop-down on the Audio panel, choose Instrument Outputs > Sibelius Mix-L Mix-R


More tests forthcomingwise. 

*So far those robots only exist on pianos.