Zuki. Don't give up yet. Good points made by all here. However, this is a different beast than the Yamaha that you are used to and endeared to. I have the G-70 and it took me a month to just get used to it. I played PSRs for 10 years and they seem to be more forgiving with your chord fingering. If you play the chord correctly and on tempo it will give it to you perfectly.
My second post on this board after I got the G-70 was THIS MIGHT BE TO SMART FOR ME.
As an organist I found that I had become
sloppy with my chords (3-4-5 fingers). Once I tuned up this thing was a whole different instrument and became a real PLEASURE. The key feel and the 76 keys are unsurpassed. You should really try and spend some time with it.
I play 4-5 NH gigs a week (I assume you are playing this venue by your Begin the Beguine example) and have never felt that the styles are to busy.
Try a few diffent styles that you might think would work. For example with Begin the Beguine try the Bolero style in the Ball room styles. Even in the Music Assistant there are great matches. Try Sentimental Journey with OTS. Awesome. Or Ticket to Ride with Live Band, Real Band. And if you can sing the VH is as good as it gets. Give it a little more time cause it doesn't seem that you are under pressure to have this up to speed right now. Hopefully the more you play and explore you ears become more comfortable with what you hear.
And if this one doesn't work out, good luck with the next one.
Stay Happy
ScottC