I've owned a couple 2009 touring models (a Road Glide and a Road King).....notice the past tense in ownership.
I still own my 2002 Road King because it is extremely well built and stable....including stability at high speeds (100+ mph) and fast/sharp corners. In my opinion, there was not that much of a difference in the handling of the new bikes. I'll give a slight advantage to the Brembo brakes (which you can put on a 2007 and older bike if you wanted to). I did find the new frame handled slightly better in high speed cornering....the type that most would never (or rarely) attempt with a bagger anyway. So in my opinion, the new frame is not some incredible magical design that totally transforms these bikes.
But, my 2002 Road King has some things that the newer bikes do not have. It has a stong bottom end on it TC88....forged crank, timken.....and each year the newer engines have fewer parts in them, almost as if they are going "disposable". Funny how HD has been able to lower the price on the newer bikes, or keep them about the same. Something is getting cheapened up to accomplish that.
If I were in the market for a used bike, I would not walk away from the older bikes.