With True Image 9, I backup to hard disk first, then burn the files to DVD afterwards. You can split the backup into any size chunks you like.
I have done that, but sometimes it would be easier if we didn't have to plug the PC into the network, or add another disc.
If we want to plug a machine in, which isn't registered on the network, we have to apply to our network support bods, and then wait between a few hours and a week, depending on how efficient they are. There are ways around this (shift MAC address, and use another machines IP), but it's a pain. For an old machine with a 10 or 20 gig hard disc (or even smaller), a quick one time backup directly to a DVD would be handy.
Some machines don't have USB interfaces (we have still operating machines which are over 10 years old).
I'll probably buy a newer version of Acronis at some point. The main issue that stopped me last time, was finding someone who would sell us a copy, and who was registered on our purchasing system.