I have been using Time Capsule on my Mac Pro and my wife has been using it on her MacBook Pro for regular and routine backups. She got her MacBook in February and I got my Mac Pro in October. We're happy.
But I'm backing up to an internal drive. My wife to an external drive. Our Time Capsule is shared storage that is mounted on either computer with a password. If I need to send her a file, I just put it there. Periodically, I clean it out.
I purchased the 1GB Time Capsule about 18 months ago and I have very fast Internet access.
I did try to use it for wireless backups with a G4-400 for a while and that was too slow, but that is due to the speed of 802.11b. That was too slow for reliable backups.
I do note that it tends to run warm. But I have not had a problem with it yet.
I've seen people talk about the Time Capsule being unreliable because after 18 months it dosen't work, or it slows down the person's internet connection. Is this a real problem in the Time Capsule or is it a few rare cases?.