Danny...there are experts on this forum, that could give you advice regarding any of the Current TOTL and MOTL arrangers. Also, if your looking to enhance your sound options, there are many here that could assist you with Yamaha or Korg options.

Some simple questions might be:
Are you playing live?
Are you a home recording artist?
Do you feel the T4 provides all your arranger needs?
Donny’s right...you sound like a yammie arranger guy. So Genos is the top. If you need to drag it around...could be a problem.
You would probably be better off selling the T4 now as the value will continue to slide as newer models are released.

Again, there are masters of about every arranger keyboard on this forum.
Just ask for specific AK questions.
JM