Hey, give it a chance !!!
Seriously, you dont appear to of had it for more than a few days and you already want to sell it?? Surely, it cant be all that bad. You have possibly the best keyboard out there in the shape of the X1. It would be a travesty to sell it then later to find that it was the one after all, especially if you got it for a very good price as you say.
You appear to have a lot of extra features at a good price, not even I have some of the features/items you have, eg, vocaliser & carry case. What dont you like about the X1? If you miss the Yamaha styles, just say the word and we could send you the PSR9000 styles to you so you can play them on the X1. But surely, the X1 should of blown you away with its styles. I mean, the PSR740 is a great keyboard but the X1 is in a different league. If you got the PSR9000, you may find that its quite similar to the PSR740 that you already own, except of course its more professional and has more features.
Why dont you give the X1 another go before you make a hasty choice to sell it. Experiment with the styles on the HD, you have a lot of styles in FOLDER 1 for specific songs, they are brilliant.
DannyUK