1. It should work great for huge files, especially over LANs. Right now a 1byte change will mean a re-download, but one of the first things we're doing is introduce diff-based downloads :)
2. It should
3. We're not 100% sure how we're going to charge for it yet, but anyone who signs up for the beta will be grandfathered into whatever system we end up using (i.e. you won't have to pay)
4. I'm actually going to address this in a separate post, but we've designed it in such a way where you'll actually stream files from one device to the other (based on a least-recently-used policy), so in effect you should have access to ~104GB of data.
5. This relates to #4, but is up to you, largely. If you have computers that are up 24/7, great. If you don't, you can leverage our cloud servers for better availability.
#4 is interesting—but how do you define "devices?"
I have, say, 500GB of music. It doesn't fit on my laptop, so it "lives" on an external HD. Could it sync the laptop with the HD so that I always still have access to a set chunk—say, 10GB—of my most-recently-used music files? This is a capability I've been waiting for something to support ever since I bought the drive.
a device is anything that can run AeroFS. We can (and plan) to do exactly what you described for caching data in between _devices_, but we haven't really considered the use case where you may want access to your most recently used external HDD data (in this case, the external HDD is really more like a part of your laptop device)