I just stayed at the Occidental Grand. Good resort. Rooms were upscale, nice pools but the food was meh. Did not use the house-shop. We used Palancar Divers and they were great. Picked us up at the pier every morning at 8:30am. 5 minute ride to the reefs. It's a long drive into town if you want to eat decent food. But OTOH, it's a very relaxing stay. The pools are great and the convenience of not having to worry about anything is enjoyable.
Did you have to pay to use the pier since you were using another shop? I was there May 8th - 15th and we had a diver that we picked up daily but they told him it was $7/pp every day to use the pier if you didn't use the dive shop on site. So we picked him up in the sand next to the pier every day.