Conflicting reports? Meaning?

Different partitions/harddisks for better performance and safe backups.

Better performance: while your windows and programs run from one, your audio can run from another disk(best solution). This prevents audio to "wait" for seeking time on the harddisk that your programs/system during the process will require.

Safe backup: When windows need reinstalling e.g., having more partitions or disks, keeps your audio/midi/movies/pictures and so on, save, since you would only reinstall on your systempartition.

How big? Depends on what you got and how much programs you install. I got my system partitions (I got 3 diferent partitions for multibooting) set at 30 Gb each on 3 different disks. My "safe" partitions/disks vary. For movies and audio I got very large partitions, for my ghostbackups mediumsized and for other stuff smaller ones.

For tweaking your system you might want to look into a website of "blackviper" (just google it). He has got a lot of good tweaking advices, also for the services that were mentioned in the replies.

I'll be back...