My wife and I spent her school Xmas break in Puerto Vallarta. Had a great time, put plenty of miles exploring the old section on foot. Loved the taco stands, we had several suppers just sampling all the different stands we could find. The highlight was landing a sailfish the captain guessed was about 80lbs.
We would (will) go back to PV, no question. Really the biggest negative I can say is the Pacific Ocean isn't nearly as warm or clear as the Caribbean, which is a bit of a downer, but there were plenty of positives.