I wouldn't personally make such a switch. I kind of view the two hotels as one resort. Yes, the hotels are a bit different. However, they share transportation and the Grotto pool. They are right across from one another so you can easily take advantage of the restaurants in either. Not that switching is a lot of trouble, but it doesn't seem to get you much if you go from one to the other.
That being said, we do like to switch resorts sometimes. Our December trip this year will be split between VWL and BCV.