There is a weight difference between PA4X and T5. PA series is made of medal and the Tyros is plastic. NOt sure of exact weight, but probably 10 lbs heavier.

I've never been happy with the feel and touch of T5' Function Buttons. As you know, you use F1 thru F10 to navigate through the Yamaha menus.

I think you'll find the touch screen on PA series to be better to navigate vs. Tyros.