Having owned both an Audya 4 and a Korg Pa3x, i can state that the T5 as a whole package blows them away in ease of use, soundquallity and playing fun..

I love the styles of the Audya, but Yamaha is not far behind
I love the extra features and edditabillity of the Pa3x..

But the SA2, organ world and ensemble voices are just to much fun to play with to ever move back...