I don't want testing. Stable is fine.
I find each version of Ubuntu worse than the previous. It's change for the sake of change, and as in this case, something really thoughtful like .deb gets replaced with something which appears slapped together poorly.
I just want a stable, working system, and Ubuntu seems to no longer be the way to have that.
You may also want to keep some places like /var/lib/ if you have databases going, etc. I'd just do a complete backup and restore pieces as you find you need them.
The only pain I can come up with is that I'm wasting about 20 GB, because the operating system doesn't actually need 50 GB. So maybe not a great solution for people who have to do with Laptop with a non-replaceable 128 GB SSD. But 20 GB is not a big deal to me.
The upside is that I've done clean Ubuntu reinstalls two or maybe three times since then, and my data was a non-issue, just reassign the existing partitions and don't format /home. I'd estimate it takes rather less than the 30 minutes the paines refers to, and I always grin despite myself when Firefox restores the browser window as if nothing had happened.