So as for the harness fit, I'm not familiar at all with these amplified systems like you have - my Honda install was on a standard '06 plug 'n play. I did find, however, that working with Howard at quickconnectproducts.com, he was very helpful about questions and working out config issues with me when I was getting ready to install on my 07 Freestyle (ford has an odd harness for radios with the phone mute button). His web site says that if you have an issue to send him a pic of the rear panel and they'll work it out - so since you have the pic, let us know what he says for others going to install in the future on the '08 EX-L! I do know that the harnesses work great!
As far as why to get a CK3100 - if you don't have the Nav system, then this is by far the cheapest way to get bluetooth along with a display of incoming calls. It works great and installs very quickly - and for under $150 for the unit, is a great buy! I have one each in the Freestyle and Montego, and the one in the Montego was moved over from my Pilot previously.
