I'm a fan of both Yamaha & Korg, so not biased in any way. What I can tell you is that there are more excellent Yamaha styles available for free than for any other brand. At least 5 - 10% of that database (of way over 40 000 styles) are extremely good.
I have had my old PSR3000 now for more than four years, and I am still very much in love and elated by it. Must say, I NEVER use my onboard styles anymore as the newer ones are just so much better.
Something to consider.
Make sure you'll fly forever!