In a series where I hope to get you excited about the innovations Webconverger are doing, I'm going to profile what possibilities a git maintained rootfs can realise.
The ugly truth with all Linux distributions except Webconverger is that downgrading is non-trivial. You can only "upgrade" your way out of trouble. You could fetch old packages from say http://snapshot.debian.org though you could get easily run into some dependency problem. Then once you've managed to downgrade you need to put holds on the downgraded which then you probably forget about them and wonder why things don't properly upgrade from there.
Just imagine a downgrade is as simple as a git revert
... well it is with Webconverger!
Take this particular issue #16 as an example. I performed an upgrade which was found to be the cause of font rendering problems, which incidentally corresponded to Debian bug 666736. I simply reverted that particular change and now we are back on track for a new release with another innovation.