Nigel,
Sorry, I think it's a good question for me as I have no idea how programmable the T4 is as far as sounds...I can tell you that the PA2 has FULL programmability of everything on the sound except the sample data itself, and that could be substututed.

I do not want to be stuck with some of those automatic nuances in some sounds. Yes, I realise learning the correct touch on SA & SA2 is important...but on the T2 I found it difficult.