I get my creative Fix out of re-designing my layout every year (A seasonal approach). There is a certain satisfaction I get with with knowing that the planning stage is longer than the actual running phase and allows for much more fantasizing, and the tear down even faster. Don't want a permanent layout whatsoever. Accessories fit whatever the theme may be and often get a rest from year to year. Same for Loco's.
More recently the size is diminishing... at least until my wife retires 5 years from now and I get control of the Office/bonus room. But that hasn't taken any from the fun. Sometimes downsizing is a good thing as it requires less effort putting up and tearing down. Really depends on how busy we are with other things, especially travel.