Steve
I am no soil expert, but I think the soil on both courses is essentially the same. Generally sandy base, with some holes more sandy than others. If it rains, some holes are more effected than others. Basically, the lower lying holes are wetter than the holes in the dunes. The Champ course can hold a ton more water because its on higher ground. A few days of good rain will see the Channel (hard on the marsh) have loads of puddles. While the Champ course never dries out as much as many links, when the serious rain comes, it holds up at least as well id not better than any other links in the south. There can be an incredible amount of standing water, but the course remains very playable. A few winters ago was a serious shock to the system with standing water on practically every hole - never seen anything close to this at Burnham previously.
In past experience, the Channel greens were far firmer and more linksy than the Champ greens. I know the club is still progressing toward eliminating the poor watering practices of the 80s and 90s and encouraging the fescues and bents to thrive as they should. Maybe even with the water way down it may takes years and good weather to really get the turf back in shape - I don't know. That may explain a slow (very slow!) weening off water. Both courses now have new watering systems (the Channel didn't have watering previously) in place, but I haven't played the Channel since this happened. I admit that part of the reason is my fear that the greens will now be softer. That is a genuine fear because previously there were some of the best links greens in GB&I.
All this said, in my experience, the driest and fastest courses are almost 100%, the courses which don't have a watering system. I have asked and asked many times. How much water a course needs is a matter of opinion. I am necessarily going to have a different opinion to the guy who relies on making a living as the greenkeeper. With that in mind, how much water do you think supers buffer in to make sure they avoid disaster? How much more water above the super's opinion of what the course needs is used "just in case".
Don't get me wrong, the quality of the greens at Burnham have improved dramatically form the days when Burnham had the rep of the fastest and best greens in England. The thing is, progress seems to have stalled in recent years. It could be down to the the last few awful winters though.
Ciao