Nah, the Tyros4 still sounds far better than BK-5. It literally blows it away. No comparison.
Sound is what is most important to a professional, not features that they would hardly ever use, if at all.
I'm a professional...I've been playing pro since I was 15, and I'm 62 now.
Why would I want to play an inferior sounding instrument just to save a few bucks and get features that mean very little to me?
If you like the sound of BK-5 better than your Tyros4, then by all means get one.
Complaining about what the Tyros4 allegedly lacks is rather silly...you bought it!
If it is that much of a dumbed down instrument, why did you waste your money on it?
You personally, might gain one or two things that you would use, with a BK-5, but it is going to sound pretty lame compared to the mighty Tyros4; but, that may not matter all that much to you.
I'm a player first, and a tweaker a distant second...the Tyros4 is first, and foremost, a player's instrument...any pro who has one will tell you the same thing...it is a dream to play. It is an extremely expressive instrument.
I hope you do well with the BK-5, should you decide to get one.
Happy playing,
Ian
PS...Listen to music made by SZ members Telmo and Joost, and by Yamaha artists like Martin Harris and Peter Baartmans. Think a BK-5 will ever sound that good?
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.