Had the IPad pro for almost a month. Had to wait for the keyboard and pencil though. Finally all three are here. I have had an IPad f one type or another for about 3 years Graqdually I have used it more and more for productivity since I have to go to a lot of meetings and conventions. My hope was that the IPad or would replace my laptop. I'm pleased to say that I a Aristide it's my decision and that I think the IPad Pro will serve my needs. To the lint that I sold my laptop. I need to find an easy way to keep all my files on the pro without using ITunes if possible. Once I am truly convinced that the pro will serve all my needs, I'll probably get rid of my desktop as well. SO, color me happy.
Other than a couple of updates to the Mac's software, I haven't turned on my desktop for two weeks. It's part of my iPad Pro only experiment. So far, mostly ok. Even after I shipped off the Air.
DropBox is probably the most commonly way to manage, share, and move files on/off your iPad. Files can be marked local, so that they are always available on your device.
There are other, similar services.
Apple's new Cloud Drive works fairly well for those apps that support it. Google Drive is good if you use a lot of Google services; and OneDrive is included with and Office 365 subscription.
Good luck, and enjoy your iPad Pro.
P.S. I'll probably end up turning the desktop back on. I'm not happy with any of the iOS's file backup solutions, and while watcing movies on the iPad Pro is good, it's still not better than a 27" iMac's screen and sound.