I am about to place an order for a 2002 Odyssey. I would like both the RES and the NAVI. However, RES+NAVI is not a factory option. I will choose to order either the EXL-RES or EXL-NAVI + dealer iVES. Does anybody know the difference between the factory installed RES and dealer installed iVES systems? Will the dealer installed system be as good as the factory?