[pengu]

I'm using a LaCie Biggest Quadra 4000GB (4 1TB disks in RAID5, 2.7TB usable) connected to my Mac Mini (which replaced a G5 PowerMac) via FW800.

This backs up the internal drive of the Mini (120GB), two LaCie external drives (1TB and 500GB) and the MacBook Pro (160GB) and a portable LaCie drive I use with the MBP for VMs (500GB).

I was backing up wirelessly when it was connected to the G5, and yes it's slow, but it depends what the majority of your changes to data are. If it's mostly things like Office/iWork documents and some pictures in iPhoto, it's not a problem. It's when you have hundreds of MB to backup that it will be a big problem using wireless.

If (like me) you have a lot of data in say iTunes, this stuff won't really change, so once its backed up it's not likely to need to be backed up again soon.

Personally, I spent quite a bit for a "home" backup drive ($3500) but that was AFTER I'd learnt the hard way, that losing data can really fuck you around.