After reading a some great overviews from Serenity Caldwell for iMore, Casey Newton for The Verge, and David Pogue for Yahoo (that still feels weird to say), I thought I'd give a more nerdy first look at what Photos is and how stable it is at the moment. [gallery type="slideshow" size="full" ids="433,434,431,432,435"]

Beyond the basic feature set, how does Photos behave, and is it stable enough for prime time?

Importing your existing library

When i first launched Photos, it prompted me to import my Aperture and iPhoto libraries. It auto-detected them, so I just had to select one and click import. It was all very painless. Photos even maintained my folder structure from Aperture.

Stability

Photos is still in private beta, and it really feels like it. Like any true beta, the feature set is pretty much locked down at this point. Everything Apple says is going to be there is there, but not everything works every time. I have been able to get Photos to crash on multiple occasions by doing all sorts of things.

On the other hand, all of the server-side stuff has been perfect. My initial photo upload was about 10GB of photos and it went perfectly smoothly. All my photos now show up on my Mac, iPhone, iPad, and at iCloud.com. As we speak, I'm doing the other half of my library (another 10GB) and so far so good.

It seems like Apple has the server side angle figured out. I have always felt comfortable keeping my photos in iCloud Drive, and I still feel great about it. Apple just needs to lock down the Mac app.

Sync

The big draw of iCloud Photo Library is that it will synchronize all of your photos across your devices. I'm happy to report that sync works as advertised. Everything from edits to favorites to albums all sync across your iCloud Photo Library-enabled devices. I was seeing edits propagate elsewhere in about 5-10 seconds. Obviously a couple hours of use doesn't give a complete picture of how well sync works in edge cases, but I have not had any conflicts so far.

What about the nerdy stuff? Glad you asked!

• There currently is no icon for extensions like there is in Photos for iOS. I hope this is planned for the final release.
• Importing RAW photos from a real camera works fine. Photos takes a little more time to process them right after they're imported, but after the initial process, they act no differently than the .jpeg's coming off your iPhone.
• Export options are kind of limited. You can choose between .jpeg, .tiff, and .png. You do have quality options as well as resizing options from the export pane. You can also strip your exported photos of their title, description, keyword, and location metadata if you're sharing them publicly. There are also a few options for naming your exported photos. They could be Christmas2014-1.jpeg instead of DSC_1554.JPEG.
• Book, calendar, and card options are still here, and the prices seem very reasonable. I never used this in iPhoto, so I'm not sure how this stacks up.