My 2007 Honda Accord has the factory headunit (XM & in-dash 6-disc changer).  I replaced the rear deck speakers with Boston S95's (good mids and highs, very bad bass).  I also put in an Eclipse sub and a crossfire amp in the trunk and now, the sound is excellent!  I don't need XM.  I just want to hook up my iPod and also listen to FM or a CD occasionally.  I know about the USA-SPEC Honda iPod adapter which sells for $150. 

My question is ... wouldn't it be better to just replace the factory HU with a brand-name, that has an AUX port in the front for $170 or so?  Why would anybody want to spend $150 on an iPod adapter alone?  Will an after-marker unit still work the dual-zone climate controls and the other climate controls in the Honda?

Please explain if you have a info/opinion - I'm trying to decide whether to get my HU changed or get the iPod adapter!  Thanks a lot.