I'll go ahead and say it because I have a long track record of championing FCP X: it's a program well ahead of its time.
If you had reservations about the capabilities of previous versions of Final Cut Pro X or drank the "not pro enough for me" Kool-Aid, you'll definitely want to revisit this version and give it a shot, as it's better in almost every way. Built from the ground up for Mavericks, it's faster, has much better library and project management, and can now handle a ridiculous number of 4k video streams at once on the latest hardware.
We Must Rebuild
A lot of people misunderstood Final Cut Pro X when it was first released; they were confused about why they couldn't open old projects and why staple features had been removed from the app. "This is just iMovie Pro!", "I'm leaving for Premiere!" they cried.
The fact of the matter is that Final Cut Pro X was not able to do a lot of things when it was first released, but it was and continues to push the envelope in what it's actually intended to do: edit video. In capable (read: knowledgeable) hands, it's one of the fastest editing programs available today. There is a learning curve, but I haven't met a single editor who actually knows how to use it that dislikes it. I have a somewhat unique perspective since I teach it on the side.
Apple has proven time and again that just because something works doesn't mean it's exempt from being pulled apart, stripped down, and rebuilt better over time. Look at iCloud, iWork, the iLife applications, and even certain hardware like iPhones and, most recently, the Mac Pro. Of course, "better" is subjective in all those cases, but you get my point.
Three Big Things
Well, visually they've tweaked a few things but under the hood are where most of the real improvements are.
The Unified Library Scared the Hell Out of Me at First
After I upgraded to 10.1, the first thing it asked me to do was upgrade my Library, which I did. After a relaunch, it appeared as though my Project Library got nuked, but alas, the new structure means that projects appear under Events, right alongside the clips.
The Library serves as a standalone file that contains all of your event and project data. Now you can create a library for a particular client and have all of their clips and projects live under it. What I've begun to do is split my libraries into categories, one for Family, Gear Reviews, Current Projects, and (though not pictured) Archived Work. It's actually pretty fantastic and at any time you can choose to close an entire Library simply by right clicking it and choosing "Close Library...". A closed Library will not automatically open the next time you launch Final Cut, which ends up saving you a bunch of load time and ensuring client privacy if working onsite.
Snapshots Are Fantastic
I don't have any projects in the works until next year, but Snapshots are something I'll be using on every project going forward. The main difference between a snapshot and duplicating a project entirely are pretty straightforward: If you duplicate a project with a compound or multicam clip and then make a change to either of the aforementioned clips in your original project, that change trickles down into all subsequent duplicates. However, with a snapshot those changes do not get applied. It's a subtle change, but with multi-angle interview footage or a large sequence you've flattened down it's a godsend.
Switch Between Media Views
If you're working with 4k or extremely high data rate material, you're probably going to transcode it to proxy media for a slightly smoother editing experience. Now you can, on the fly, switch back and forth between viewing the Optimized/Original Media and Proxy. Really handy for getting an idea of how a finished project will look!
Other Notable Features In List Format
The rest of the features are equally impressive, though I've had less time to explore them fully:
- Retime To Fit method of Replacement and Blade Speed Retiming
- Active clip indicator (a small, but useful addition!)
- Ability to fade audio component individually
- Better Keyframes, including copy/paste functionality
- New Stablization methods
- 4K Export to YouTube
- Updated XML Export
- FxPlug 3, which should make your favorite plugins like FilmConvert, HyColour, etc look even better
Upgrade? Hell Yes!
It should go without saying, but don't upgrade if you're in the middle of a project. Also, remember that if you're running an older version of OS X this is going to be a two-fold upgrade: once to Mavericks, then to FCP X 10.1 so make sure your other software is compatible as well.
The speed improvements, new library structure, and other UI tweaks make this update well worth your time.