The Tyros3 has the exact same keybed as the Tyros2 i.e. the FSX keybed.
As far as there being weights; there are also weights below the T2 keys although they may be located at a different spot than the weights on the Tyros3. Someone else noted that the T3 keybed felt 'better' than the T2's keybed. The placement area of the weights on the T3 (if they are indeed located at a different spot than the T2's weights) could be the reason why the keybed on the T3 feels "better" i.e. - feels like it has a better action.
That's the only reason I can think of anyway, since both the T2 and T3 have the exact same FSX keybed.
Best,
Mike
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Yamaha Genos, Mackie HR824 MKII Studio Monitors, Mackie 1202 VLZ Pro Mixer (made in USA), Cakewalk Sonar Platinum, Shure SM58 vocal mic.