Shaun,
You may remember I have a few Harry Potter-themed modules including both Hogwarts and Hogsmeade Station. I find that being a member of a modular club allows me to challenge myself by trying very different themes in a 4' by 2' space. For example, maybe you always wanted to model a tropical beach or a haunted cathedral ruin, or maybe Lawrence of Arabia's attack on a train, or something very, very different. Modular clubs let me pursue those impulses and helps refresh my mojo. If I was modeling a single layout and a single theme for a period of years, I don't know where my mojo would be.