With the two 2003 bottlings, I keep flip-flopping. Right now I'm leaning toward the Spring, not necessarily because it's better per se, but because I'm really intrigued with the 'dark fruit' notes it has. If you're new to tasting, or think tasting notes are a bunch of hooey, try Spring '03. You'll be writing your own notes with language like "black cherries", "plums", "raisins", etc.
Fall is less unique, but probably more balanced and in the strictest sense a better overall bourbon. Nice spice notes.