In Retrospect, Retrospect Sucks
I've been using Retrospect for backups forever. It came free with a drive I bought a while back, and it just seems like the thing to use. But prior to prepping my Powerbook for return to Apple, I tried using Carbon Copy Cloner instead.
Aside from being free, the big win is that it makes a completely accessible and bootable backup of your entire drive. I don't care so much about being able to do incremental or journaled backups - I really just want to know that there is a fairly recent copy of my stuff on my backup drive that I can access and boot from as needed. Once you get past a somewhat clunky GUI, CCC fits this bill perfectly.
It also makes it trivial to migrate your entire operating environment to another machine: just mount your destination powerbook as an external firewire drive (hold 'T" at startup), and use CCC to clone from old machine to new. Start up the new machine and everything just works. Brilliant.
Actually, SuperDuper seems to have largely superseded CCC -- I didn't follow the particulars of the discussions enough to know exactly why (I think SD is just more actively maintained and developed), but it's extremely well-regarded by the Mac community.
Shirt Pocket Software, the makers of SuperDuper, seem to be one of those Mac developers we all know and adore: heroic support, top-notch software with a great UI, and very reasonable prices. (SuperDuper will even do everything CCC does, I believe -- at least, the whole dup-one-partition-to-another-wholesale -- without you even registering it.)
And, yeah, Retrospect is generally considered ass. I still remember in the days of System 7 when it was probably the best backup program on any platform. But those days are long gone (take that, you Veritas bastards :-).
There still is no decent way to back up a large amount of Mac data to optical disk, AFAIK. I used Toast 7 recently and had it span disks -- it worked OK, but it burns Mac-only disks if you do that and has one huge bug: if you run into a burn error on a disk in a spanned config, it simply skips that disk entirely and proceeds onto the next one. What about the data that was supposed to be on that disk? NO YUO. All gone.
Yeah, I played w/ SuperDuper as well. The GUI is definitely nicer, but I didn't see anything that made it worth coughing up $30 for. As you say, the free version only does wholsale; I wanted to be able to exclude a couple of directories.
As for optical: Yeah, I'm actually not really burning anything at all anymore. Partly because the software sucks, as you note. Even with the best imaginable software, though, a 3-400gb hard drive is going to be far more convenient, and they're now cheap enough to be cost effective.