Hotels generally get more luxurious and expensive the farther north of the Río Cuale you look. The far northern section, on the marina’s ocean side, with a line-up of several big international chain hotels, is isolated several miles from downtown Puerto Vallarta [1] and has only a narrow beach, often with more rocks than sand.
Most of the central part of downtown, which begins at the Río Cuale and stretches for about a mile north along the Malecón, has no good beach except at the far north end and is generally too noisy and congested for comfortable lodgings, with some exceptions.
Links:
[1] http://www.moon.com/destinations/puerto-vallarta/puerto-vallarta