A keyboard and a sound card is really convenient for the stage and space saving.

UTILIZATION

I tested the touch. Stop comparing the incomparable! This is a synthesizer MIDI Keyboard Controller not a digital piano-_-! Touch to a synthesizer is really nice though biensur is not touched a digital piano.

OVERALL OPINION

I did not but compare it to RD300sx seem to me very unlikely. Where do you get the relationship between a master MIDI keyboard and a digital piano 300euro to 1300? The comparison would be to compare an electric guitar and an acoustic guitar for the same purpose). Indeed, the utility is absolutely not the same! The built-in sounds, I did not test but if they are not well, remember that the goal is to import sounds: This is a midi keyboard!
So this keyboard is for the person who uses several types of sounds and not seeking a touch of piano. Also, if you own the software Pianoteq, the printing on the keyboard will change a lot!
I received in about a week and I re-file a notice after having actually tested.