Thank you all for your responces. Finally, I ordered the Roland VA-5. Basically, my main dilema was between Korg and Roland, but after seeing the PA's screen, all was clear. I just couldn'g buy a keyboard with this screen for that money. 1/3 plain old LCD, and the rest 4 lines of poor dot matrix? Thanks but no thanks. I will be very happy with the 320*240 touch screen of the Roland... You may find it funny, to decide over a display, but since the sound quality of both keyboards satisfied me, the Users interface was the second most important factor.
Plus that VA has 128 (korg 64)notes polyphony, 48MB of samples and the V drums (drum sounds recorded already mounted on a real drum set, with the natural resonances! Hear it and you'll agree)...
So, tomorrow or monday I'll have my new baby... Thanks again.