I went to town on an AirPort Time Capsule — by myself — as a means of not making the other tech writers suffer any more than they have to. They've been working hard on yet another teardown; in the meantime, check out my AirPort Time Capsule (mini!) teardown.
Here's the details:
* Hey, it has a standard 3.5" Seagate Barracuda SATA drive!
* Time Capsule repairability score: 8 out of 10, same as the Extreme. Nothing new here, since it's basically the same device from a repairability standpoint.
* This is the port that the Time Capsule has, that the Extreme doesn't:
This port allows the Time Capsule to have a hard drive plugged into it. Folks asked us if it's feasible to make an Extreme into a Time Capsule. Theoretically the answer is "Yes," but we're not sure why you'd go through the trouble — the Seagate Barracuda drive is essentially the price difference between the Time Capsule and the Extreme.
Check out the full (mini) teardown for more info.
Quick update: The Time Capsule will easily accept a 4TB 3.5" hard drive in place of its lowly 2TB original drive. The Seagate was used to take this screenshot, but the HGST drive should work fine as well.