IMO Alpine is the premier head unit manufacturer. The sound quality from the Alpines is unmatched by any other manufacturer. iPod control is 10x better than the Kenwoods and the Kenwoods are so confusing to use (even to an experienced installer).
They both come with their own version of the time alignment software and if you are planning on using this feature then I would seriously research it and see if you want it. If you AREN'T going to use it then I would go with the CDA-9886.
The reason the Alpine's have such better sound quality is because they are all Imprint Technology ready (the 9887 coming with the necessary hardware/software in the box). To be able to support the Imprint technology, all of the head units had an upgrade in their microprocessors resulting in better SQ.
To me, there is nothing really special about Kenwoods, the 5V pre outs are nice but Alpine's 4V will sound better. Both are bluetooth ready, the Alpine has a USB cable and iPod cable...who really needs a memory card slot with those two options? And, the Alpine comes with the Ipod cable whereas you have to buy it from Kenwood.
$.02