Yeah, the biggest problem is all of the adapters needed to retain your factory controls, connections and other fuctions. Plus the stock speakers (especially the non premium model...which is what I assume you have) SUCK.
It isn't like the old days where you could swap an HU, add an amp, and go about your business.
Now, everything is run through the CANBus, so you have to have an adapter for this, and an adapter for that, blah, blah, blah. Do you have Sirius and/or Connectivity?