Lou,
Heavier soils will typically have greater water and nutrient holding capacity. Heavy soils tend to have a greater buffering capacity, they have fewer swings from wilt to lush and from dry to wet. They hold more water and stay wetter, but if allowed to dry out it can become very difficult to get them wet again. Biggest headache on a golf course with heavy soils is compaction. Heavy soils stay wetter longer, wet soils compact more readily, once they compact you can't get them wet or get air to roots, you lose roots, plant dies. Therefore, once you get a little behind with your aerification you enter the death spiral that is hard to get out of without significant work. Best thing to do on heavy soils is manage where getting air into the rootzone the number one priority.
Now, to your question about managing golf turf on sand vs. loam. Yes, sand is a better medium to grow golf turf on because it drains. Sand drains well because it is very course and has large pore spaces that move water and equally important allow air exchange. Your question is grounded in an ag approach, as in isn’t it better to grow plants on a richer soil? In most cases, yes. In the case of growing good golf turf the answer is, it depends on what you like. If you like lush, thick turf (and we know this is what most like) then more nutrient and water holding capacity is better so loam is a good choice. But just because you may use less water or fert, don’t think there are fewer inputs as like with almost all preferences, your just exchanging one set of inputs for another. For me, sand is superior for its porous properties, but also because it does not grow “good” grass. I like growing grass on poverty soils and I’m not going to give the grass everything it needs to be happy because I don’t want it happy. I strongly feel that a thinner stand of grass provides a better golfing surface. That may not be true with all grasses but I know it is with Bermuda.
Here in south Texas we’re basically on heavy soils. We did sand cap a lot of the course but that cap has already started to take on the characteristics of the parent material. Sand plating will always eventually take on the characteristics of the parent material which is one reason why USGA greens needs to be rebuilt and why I believe they shouldn’t be the first option in most cases. Take a five gallon bucket, fill it half full with a clay loam and then spread a 2mm layer of sand on top. Put it out in the weather and check back in a month to see what the top layer looks like. Its going to eventually take on the characteristics of the clay. My fertility plan here is to give the plant what it needs in a manner in which it can take it up. I do not rely on complicated soil chemical reactions to free up nutrients for the plant. I don’t spend tens of thousands of dollars trying to change the pH of the soil or amend the parent material. I can’t do it, at least not without spending huge sums every year. So I give the plant the minimum of what it needs and try to keep air in the rootzone. I believe that approach, in general, can work just about anywhere.
As far as standing water in the bunkers at Pac Dunes, sand can compact and lose some drainage capacity, but usually not enough for standing water to be around for very long. I walked TOC after a rain and never saw a puddle, but that was in the summer. You can definitely fill the pores in sand with water faster than it can drain so if it had been a lengthy wet period, which is very possible in coastal OR this time of year, then the sand was probably saturated. Just a guess on my part.