If you don't listen to the Yamaha demos on a pair of Tyros speakers, why on earth would you EXPECT them to sound the same...?

Play the T3 through the same system you listened to the demo on... and take the mastering into account. Every single thing you hear on the web, on the radio, on a CD (other than some user produced demos here and there) has been run through an EQ, a compressor and a limiter. And, I'm sorry, but the ones included in your arranger's Master Output section are TERRIBLE compared to even quite inexpensive software tools, yet alone more high-end gear.

These will impart a sheen, especially when used by those that know what they are doing, that you can't necessarily emulate live... Nor should you. There's too much compression on your stuff already, probably. Take it all off, and the darn things might actually sound LIVE for a change!

You will certainly have a better idea of whether the style and keyboard section is balanced to start off, which will ALWAYS make for an easier track to master when you finally DO get around to that (if you are recording yourself).

I'm sorry, but expecting ANYONE to post unmastered audio these days of anything at all is just not realistic. Otherwise you'll be constantly turning your computer's (or home stereo's) volume knob up and down like a madman as you go from mastered to unmastered material.

Mastering is an essential part of the audio chain these days. Neglect it at your peril!