Ben,
Generally speaking, Celebration seems to be less finicky on acidic soils than many other bermudas, which is great for Pine Tree because we had several fairways with pH in the 4's, upon my arrival. We have such ebs and flows with rain in south Florida, and with many courses (Pine Tree included) using reclaim water, soils and salt built up are the key to growing turf, IMHO. Our soils are much more balanced now, but it certainly has been a few years in the making.
The sand allows the new sprigs something to grow into, but also allow for the Celebration to be less "leggy." In fact, the addition of sand is a 1/3 of the cost of the project, but one that we think is important as we are on old, dairy farm land.