The biggest worry of such a system would be accidental deployment. You might as well just have two life rafts, one for you and one for the aircraft!! Imagine the problems with control should the emergency flotation device inflate accidently inside the aircraft....
Personally I would rather just get away from the aircraft, into the raft as quickly as I could, in the simplest way possible.
A PLB, flares and fluorescein all add to your visibility in the water.