Sometimes a newer kernel is needed for newer hardware. Here there is a dell 17 5000 series with touchpad, sound and network not working properly.
Some info for anyone doing a snapshot using a 4x kernel, be it from jessie backports, sid, siduction or liquorix:
You need also the latest live-boot and live-boot-initramfs-tools else it won't boot. That's because aufs seems to be deprecated, overlayfs has replaced. (there is no longer even an aufs kernel module). Get them from sid (or ceres, if you run devuan), they install on jessie.
The patches we did for earlier live-boot to get rw mount of the live-media partition probably won't work till updated.
I don't know about 4x kernel and wheezy.