Of course that is all just a guess. If you want new versions quickly then switch to Arch. Just try it in a virtual machine or spare machine as there is a learning curve for Debian users.
In the mean time I am happy enough with 3.8 on testing. I have tried the newer versions through experimental and Arch, but in the end Gnome Shell does not change that much and newer versions have less extensions available as it takes a while for extension authors to catch up. We have to go through the systemd change and then Wayland. My testing "just works" and that is good.