I have only riden a Busa once , about 3 years ago , and WOW ! there fast , but they are also comfortable and have a low seat . I am looking out for one at the moment ,the Blade that I have is a great bike and as quick as you will never need , Ihave seen 180mph on the speedo , but it really lacks comfort , but the Busa , ther comfoy ,and fast .
All modern sports bikes are fast , but it donn't mean they need to be ridden fast all the time , owning a Busa is I think as much about going as being able to go fast if you chose . If I where you I would go for the bike , but with 20k on the clock check the down pipes and rear shock , if these have not been changed they soon will need to be , also expect to do a fork rebuild