I've jumped from Debian 7 to Debian 9 without issue, and the Gnome Software Center makes installing apps a point and click process (reminds me of Click N Run from Linspire...).
There are notable fit and finish issues with other distros, but from what I've seen the Debian package maintainers consistently make decisions to protect the package archive from breakage, whether that be holding back a FreeCiv point release over a buggy UI element, or stripping out non-free parts of Chromium that upstream bundles.
There are notable fit and finish issues with other distros, but from what I've seen the Debian package maintainers consistently make decisions to protect the package archive from breakage, whether that be holding back a FreeCiv point release over a buggy UI element, or stripping out non-free parts of Chromium that upstream bundles.