Ike,
I have to go with Sabre... the Marine Corps is probably one of, if not the most, important things I've done. Without going into my life story, let's just say it turned me around in SO many ways. As for "pros/cons" I don't know. Obviously quite realitive, but in the end I think it's similar to the Navy in many of the more important ways.... tradition, honor, duty, etc. When I was deciding on getting a commision it was the Navy or Marine Corps... NEVER considered the other two. No offense to anyone, I'm sure they're good...but not for me.
Like Sabre said, my heart will always be with the Marine Corps in many ways, but at the same time I'm sure the Navy will play just as important a part/role in my life. In the end, it's just two different chapters in my life... both are important... just the Navy is more appropriate for what I want at this stage in life. I'm sure it's similiar to the civilian world everyone else is giving up to head to P'cola.
I'm sure your friend would just as proud of your becoming a Navy officer...hell, you could of had him salute you... lol