Obviously the Time Capsule hardware itself isn't all that interesting -- after all, it's basically just an Airport Extreme with a hard drive inside. It's quiet, but definitely not silent. It does have a fan that vents out the bottom, but overall it gets and stays pretty warm -- almost hot, even. Using Time Machine is just the same as if you were using a local drive, just a little slower depending on how fast your connection is. Over 802.11n WiFi the hit was only slightly noticeable while searching, and almost non-existent over Ethernet, large transfers excepted. There is one potentially troublesome issue, however: since OS X doesn't appear to prioritize network activity out of the box, Time Machine absolutely slams your network interface when it starts up. Although browsing and other casual activities are relatively unaffected, there is definitely a noticeable impact. Just to isolate what we're talking about, this is how fast our Ethernet-connected iMac was able to send data over the LAN when it was in the middle of its initial 10MB/s backup:
If you're editing huge files all day long, that could be a problem since Time Machine kicks in every hour (unless you hack it to slow down). If not, though, you probably won't even notice the switch from a local drive to Time Capsule -- we didn't experience any similar slowdowns after that initial backup. No, the big changes are in how Time Machine handles the Time Capsule drive, and the new, refined Airport Utility.
So what's the big change in how Time Machine handles Time Capsule drives? Nothing, apart from the fact that it actually sees them. Just like the computer-connected shared drive we've been backing up to for months, Time Machine mounts a sparse disk image from the TC drive, backs up, and unmounts it -- no secret sauce or voodoo involved, as far as we can tell.
The just-a-drive nature of Time Capsule also means that it can't do a lot of the things a lot of readers asked about: sure, you can put your iTunes library on it, but it's not a media server, and pointing several computers to the same iTunes library is asking for trouble. Similarly, you can't stream directly to an Apple TV or 360 or whatever -- it just doesn't show up.
The new Airport Utility is very slick, walking you through all kinds of network setups (including complicated dual-5GHz / 2.4GHz systems and WDS chains) and even providing semi-real-time diagnostics:
Overall, Time Capsule does exactly what Apple told us it would do: make it easier for the vast majority of users to start backing up regularly over their network. That's to be commended, and if you're a Mac user and you've got the coin, there's no reason not to consider a Time Capsule when the time comes to replace your router -- we've always found Airport devices to be rock-solid, and Time Capsule is no exception. But if you're using a PC, it's not like you need the Time Machine support -- and if you own an Airport Extreme, you have every right to be peeved about the fact that what's essentially the same hardware won't let you back up to AirDisk. Let's hope 10.5.3 makes Time Capsule a little easier to swallow.