First,thank you for a clean and thorough answer!
I thought it would be convenient to a recovery partition on the HD in case I lost my USB, again. If the HD totally fails, then I really can't save it anyway because that would be beyond any recovery operation. At least that's my reasoning.
I will certainly look into the different backup options. If you come back to this thread, can you shortly elaborate why it's better to choose another backup option than TM?
You're welcome. I've had a few unfortunate incidents with Time Machine backing up to a network drive (Time Capsule). For this reason, I consider TM a nice to have and I consider something like Crashplan, CCC, Carboniteor SuperDuper a must have. By all means go ahead and use TM only don't assume it's "perfect".
One situation where I lost data was the power supply in my 1st gen TC died and when Apple returned it, all the files were gone. Meanwhile my daughter's Mac mini died while the TC was off being repaired.
Another situation where I (almost) lost data was when I was upgrading to Lion on my wife's Mac mini. At some point, possibly due to some fat-fingering on my part, her HDD got wiped. As I went to restore it, I was told the TM backup was "corrupted" and there was nothing that could be recovered. That's when I downloaded all her stuff from Crashplan and it all came back.
I've had numerous times where TM popped up and told me it was time to "start over" for the TM backups of my MBP. I simply click yes and resign myself to never being able to browse back to the 2009 version of some file. And yes I have Crashplan providing a second safety net for my more important files.
When I upgrade a Mac, often I use CCC to clone the drive. Another technique I use is to create a brand new fresh TM backup on a USB or FW drive then install the OS and "migrate" from the backup I just made. Once I'm satisfied everything is working on the new drive, I wipe the old one and pass it on to another family member. I would never attempt to migrate from a "stale" TM backup as I'd be worried it might somehow be corrupted. Creating a "fresh" TM backup can take overnight but at least it's unattended.
hope this helps...