I've been living in Mayaguez during four years because Im a student at UPRM but I used to live in Camuy (a couple of minutes west of Arecibo, for those who dont know about) and well... been in both places for such a long time I could say Mayaguez is by far more developed than Arecibo, downtown or anywhere else inside the municipality. The only advantage Arecibo has is that you can get to it using Highway 2 or expressway 22 but in terms of commercial, residential and industrial development, Mayaguez is way ahead. Although in population both are similar, Mayaguez urban area is larger and more developed maybe because there are more and larger universities than in Arecibo. Also I have to mention that nearby towns such Hatillo, Barceloneta and Manati have been growing faster than Arecibo itself in the last decade moving out developments to the respective towns.
...and about Altobello yeah you are right, it hasn't started yet but is a new project going on in Mayaguez so I mentioned it. Thx for the reply
Thanks for the info, a ver si puedo postear par de fotos