Overclocking always causes "harm" to your cpu and hardware. They are made to run at a certain frequency and voltage and last longer than the warranty. If you adjust the voltage or frequency too much then you will start decreasing the suitable life of the silicone.
How high you leave your overclock needs to be weighed out by you, but as a rule of thumb unstable is bad.
Generally speaking I only overclock more than 10-15% when I am to the point of thinking about replacing hardware. If you are to this point, then it probably doesn't matter if the life of your hardware will be decreased.
If you would like help getting your OC tuned in and making it stable at 4.4, post around here, there are many people experienced with O\Cing that can help.