Sorry, Zuki that you are having so much trouble.
When you say the fills aren't acting the same, what do you mean? The variation buttons aren't responsive? That happened to my PSR3000's and it was inexpensive to repair.
I owned two PSR3000s and I had various repair issues. I think that in the three years that I spent about $200 in repairs on both instruments.
I think that two PSR3000s or PSR-S900s are a safer bet as far as trouble free gigging than one Tyros 2.