Kudos to your friend, Andrea.

Being strictly a non-pro player (not that I could be a pro even if I tried) I want to say that a better keyboard will definitely make ME sound better, and I believe will make a good player sound EVEN better/believable.

Technique is one thing, but to convince the audience that something serious is going on, you have to have the sounds as well. When you play a sax, it has to sound like a sax, not like a drunk mosquito, or people will say it sucks. (Here's a rhyme for you). Of course sounds alone will not make a fingerless/brainless man play, but at least can help him save the day (another rhyme).

I realised that, after playing with Hypercanvas and HQ Orchestra for a while. Just hearing the same old styles of my keyboard through the Hypercanvas sound engine, I was blown off, it made me/encouraged me to actually play better, because I could milk more expression out of the Hypercanvas sounds, and sound more like "the record". I even uploaded a song for Synthzoners to hear, I was that happy. Same with the HQ Orchestra Concert piano. I never realised I could sound like that. Experienced musicians would instantly recognise an amateur with no left hand, but I could convince my friends (the actual crowd).

Ok, Peter Baartmans is a good player but if he plays a toy instrument, people will recognise, (in their subconcious at least) that a good player is playing a toy instrument.

All said and done, I believe customers will not give a damn, if you can just make them happy. In the end they won't be able to remember if it was the Roland XP-80 piano, or the P-60, or the Tyros, they will remember that the "guy playing the keyboard" offered them a good time. But I also believe that it has to be a decent arranger of a decent standard, Korg i3 and upwards, maybe a Casio WK, but not a Casio lighted keyboard.
Theodore