I have a T4. My student has a 910. I play them both quite a bit. The S910 is truly one outstanding keyboard. But, I think you maybe need to try them both again, because somewhere along the line you missed something. The sound of the T4 is so far beyond the 910 it would be really hard to miss.

If money is not an issue, the T4 is the one to have. A no brainer.

As far as the money. For example, the soprano saxes are incredible. Google the price of a Selmer soprano sax. The sax alone costs about the same as what we can buy a T4 for.