The Logitech's are every bit (and probably better) sounding than the Tyros speakers. The only real ADVANTAGE of the Yamaha TRS MS01 for Tyros owners is that they were specifically designed for mounting (as well as swivel 360 degrees) on the Tyros keyboard itself.
I've found Yamaha's decision (with the Tyros) to go onboard speakerless to be a GOOD one as the TRS-M01's offer the sound quality (+ MORE) of the former 'top of the line' PSR9000 model without its bulk and weight: over 50 lbs
. A lot easier to transport the 27 lb Tyro with the 16 lb TRS-MS01 satelite-subwoofer unit carried separately. Connection time: under 10 seconds.
Scott