Pheebs, I am with everyone else here. We follow the tales pretty closely and that piles of decapitated tourists stuff is pretty off the wall. Never heard that one and it's safe to say it didn't happen. I can think of precisely one murder of a gringo on the beach in Baja in the last 5 years or so and that was a robbery of a guy that had been living by himself in isolation for years.
Where to avoid? I would not cross at El Paso/Juarez. And there has been a group holding up people on the little road between Alamos and El Fuerte off and on for over a decade and they recently took a shot at a rider that ran the road block (first mistake right there).
Otherwise it's been awhile but I have ridden down Mexican Rt. 15 to Mazatlan and had a great time.
Where to go? San Carlos is a gringo sailing community and quite nice. Mazatlan is a really touristy city with plenty of beach resorts. El Fuerte is a dusty little town but holds good memories for me. Alamos is a small town with an artist's colony and several US celebrities used to have houses there - didn't do much for me but many people like that town.