You might have better luck getting an answer to this question on the PSR Tutorial site.
I’ll check it out! I sold a bunch of the Yamaha YST-MS50 2.1 systems back when I was selling. It’s the same wattage... 20w x2 and 40w to the sub. I still have it hooked up to my living room TV.
I did not buy the speakerset for T4, but since the Genos set got good reports I added it to the G deal. They play good at home, and maybe they will do well in smaller room gigs with few people, or also as 'monitors' when play at larger occasions. Worth the $$$$$ ? Depends of what way of use I think. To me it is, because I don't have to power up the big STK's when I'm tired using headphones...