I stayed at the Sheraton PV for 10 days at the end of December/early January with my husband and 2 daughters. Overall, we were satisfied with the stay. I suppose it helped that we had re-booked it when its category changed from 3 to 2--it saved a whole bunch of points. I did go ahead and pay an extra 10K points (1K per night) to be upgraded to a Towers room. I agree that the I didn't find the service at the front desk to be great, although I found the servers at breakfast and happy hour to be good. I also didn't find the food to be wonderful at either breakfast or happy hour, but seeing as we did feed 4 people for only a 1K points, I was pleased. The breakfast was continental, but provided enough variety that everyone was satisfied. I do wish that they would have provided beer at happy hour. Wine and champagne were the only 2 alcoholic beverage options, neither of which my husband or I care for. My daughters were able to get soda.
I would agree that our room was basic and dated. Also, we were about as far from the elevator as you could get, so that meant a long hike to get to our room.
The biggest plus for the Sheraton in our opinion is its close location to downtown. For my husband and me it would have been walkable, but with the two kids, we just took the bus in (which picks up right in front of the hotel). The location alone is enough for us to pick it over the Westin. However, we did not see the Westin, so maybe if I had I'd change my mind about that.
I can understand the OP's disappointment after booking at an expensive rate and receiving poor service. I'm sure my satisfaction with the property is colored by the fact that I had 10 days in Puerto Vallarta for only 45K points.