So far True Image has been the most reliable system of the many that I've tried. Performance is comparable to the others and decent unless you go for Max compression but they all suck when you do that. Only have an issue with the containers, as you call them, if I'm trying to extract or restore files with a machine that doesn't have True Image installed but most (all?) professional backup programs have their own proprietary containers as well. Ran into that issue when I needed to pull some files from a Macrium backup after I stopped using it.
I currently only use a clone/mirror process like you describe to backup highly volatile files and my downloads. Tip - Beyond Compare by Scooter Software is an invaluable tool (and cheap) for comparing and syncing files and folders.
Like I said previously YMMV, I've had some terrible experiences with stuff others here love and the vice versa is true.
I do try to keep regular full backups. I don't have a PC dedicated to audio, I can only budget for one high performance PC so I've got all my stuff on it. It literally takes me a couple of months to reconfigure my system after a fresh Windows install. Between installing and configuring my various audio apps, plugin installations / registrations, my programming apps, etc. - getting back to where I was is a major PITA process.
My sample libraries are on external drives or backed up - so while I don't have to reinstall them I still need to install and configure Kontakt, Play, etc and point them to the proper locations.
I used to hate iLok but I've drunk the coolade and have been converted. It made my life so much easier during my recent PC refresh. Not having to individually activate those plugin licenses was a blessing.
Peace out
...Steven