One thing to keep in mind too ... sometimes, it not only if the audience will notice and appriciate what instrument you are playing but if YOU will. When you are 'happy' and excited with your instrument, I believe 'IT' shows. The "IT" is what the audience sees, feels and hears. This is what they pay for.

Take away (as an example) your AUDYA/Tyros 4 and perform the same tunes with a replaced SD5/PSR910. You can get by, but I bet your facial expressions and the "IT" will also be quit different that night (just an example). It's all in YOU and if a $4500.00 keyboard brings out the better YOU, then go for it. Be who you want to be- who you ought to be before your audience and that is what they definately will appriciate.

Believe it or not, your instrument has a great impact on how you play. For the most part, with all the features and automation built into the AUDYA (and you add on the AJAMSONIC upgrade), it makes you want to PLAY!