I had Novak's earlier non-cable shifter in my previous TJ and those who have shifted both types agree the new cable shifter is a much better shifter than the older linkage style like I had. If I had the extra $$$, I'd definitely be getting one of the new cable shifters in my present TJ.
The essential difference between the Novak and the 1/3 more expensive AA shifter is the Novak makes use of the OE shifter and the AA comes with a replacement shifter. No doubt the AA shifter looks cooler but that's some significant added coin to just get a cooler looking shifter. Then again in all honesty I'd probably like the cooler looking AA shifter myself.