Keep in mind ...I have not played either model..
My observation is from viewing demos and owning previous modela (Tyros3 and BK5)..
Big plusses for both...76 keys..
Bigggg minuses for both..no touch screen..
VIA demos...Pianos , acoustic and electric..the BK9 wins
Why I would consider buying a BK9 before a Tyros5?
It seems like editing is the same as the Tyros3 on the Tyros5..and editing on the BK9 ..the same as the BK5...BK9 wins easily.
Chords automatically show while SMF play on the BK9..unsurpassed by any competition...BK9 wins..
Pricing...no keyboard is worth more than $3,000 to me..I will take an $1,800 BK9 first..
When I play the top of the line keyboards I will know what to do..