I replaced the 43 mm rake offset Ouzo Pro fork in my 5500 Trek with an otherwise identical 40 mm rake offset Ouzo Pro. I could feel a difference immediately but the difference was fairly minor and the bike now feels a bit more stable. There were somethings I liked better about both forks. The 43 mm let the bike move laterally quicker, could be better for criterium racing. I decided that I liked the straight ahead stability of 40 mm better.

Al