Went to Melb Australia on Sat and changed my T3 for a T4, I can tell you this is the big brother. The sounds are incredible, no need to tweek involved here, they have got it right, the Vocal harmonizer although major improve over prev models, has this fazing sound which I don't like, so will continue to use the Voice Live 2, The Audya will hold for sometime as it has some very great bass and drums, however the base and drums on the T4 have improved enormously, suffice that real change from performance from Audya to T4 is a reality now. Yes has less keys, but the weight reduction and the extra features make it a worthy challenger. Will hope that Audya come to the fore soon and improve a very good product once again, but it needs major ups this year to keep it in contention.