Well, we had to recently make this exact decision for our April 23 trip. We usually stay CR Tower but were going to try WL. When it came time to book, we just couldn't stray from CR and we believe we would have definitely regretted picking WL over CR.
Theming is all subjective. Personally, we think the CR is the ultimate Disney theme - Chef Mickey's, monorail through the hotel, great view of MK, etc. But the theming is not why we chose CR. Our travel party includes a 5 year old and an infant. The extra space of the CR room was essential, as well as the convenient transpo options. We love walking to MK and then returning to CR by monorail (first stop). We love the CR pool b/c it is large, has a fun slide, great view of bay lake, beach right there and best of all, it is typically deserted (at least when we have visited).
But, the WL is beautiful and I can see why people love it. If your party can get by with a smaller room and you don't mind the ferry to MK and bus to the rest of the parks then go for WL.