Hi,
just upgraded my little homeserver-truck to the next-branch. After dealing with a few problems on my old installation (no aptitude installed, somehow /bin/mountpoint was missing) I got erverything working. The update script uninstalled the old kernel but didn't install a new one, I had to manually install the packages with apt-get. After that everything is working great. Unfortunatly I can't tell why this was happening. When upgradeding to Jessie I accidently upgraded to testing and did a downgrade back to jessie. Perhaps this messed up my installation...
It seems the 4.2 kernel brings some perforamnce improvements, when copying with samba I get 10-15 MB/s more than with the legacy 3.4 kernel.
I've got a "feature request" for the kernel, too. Would you mind adding the usblp module (USB printing support) to the kernel? I'm using my truck as a printserver, too. My Canon Printer seems to have problems with the cups USB implementation and gets stuck sometimes. This is why I always used the old way for this.
Thank you very much for your effort, I appreciate it since my cubietruck is the heart of my little home network ;-)