Hey Tony,
I had lots of problems with Stretch when it was in testing. A lot of
packages (KDE, X drivers, and the kernel come immediately to mind)
have manageable but irritating upstream regressions that didn't get
patched or backported in time for the release.
I was very surprised when they released Stretch as I didn't find
anything 'stable' about the packages that I was using. Therefore, I've
stayed on the testing branch where many of the problems are slowly
getting fixed.
In terms of stability, I think Debian is one of the better distros
you'll get. Other distros achieve greater stability but suffer from
MacOS syndrome: the distro works only if you stick to the limited set
of features explicitly designed into the distro. There are
fixed-release-cycle distros like Ubuntu that seem to be perpetually
broken - you report a bug in a release and get told it'll be fixed in
the next release six months from now. Assuming that it's fixed in the
next release, you have a whole new set of bugs to deal with, and the
cycle continues.
In my 13 years of Linux experience, I keep coming back to Debian. It's
not perfect, but it hasn't ruined my life... yet.