Hey Digital i have that exact head unit in my o4+ and i used the metra harness for the monsoon system. it ended up costing me about 120 in parts (86ed the antenna adapter i dont listen to the radio) but as far as the unit its ok except for two things.
1. the ipod controls suck ass. the directory is a pain because u cant scroll \or jump through the music and once uve found one song and want to look for another after that one has ended u must search from the beginning again
2.the seperate navi unit needs to be mounted in a easy accessable location
Other than those two i love the BT for calling and for playing music off my phone
The Garmin with the Lane Guidance is great and u can edit some things on the maps from the unit like if a speedlimit is wrong or something