Well, I am a proud PA80 owner, with a 2 hours only experience with the Tyros.

My opinion is that KORG is easier than YAMAHA on programming side; but Yamaha voices are really great. Really.

Now, you will probably spend your time with your new board playing it (90%) and programming it (10%), so you should absolutely:

go to the shop;
put your hands on both boards;
evaluate how comfortable do you feel with them;
wich has the best sound (to your ears, of course).

Then take a look in your pocket, decide if your choiche is worth its price and ... have fun!