The Tyros 4 has a much better keybed and to me that's very important. You might even look for a used T-5 as prices are
getting better as it ages. I have played the 970 and the
keybed is to me a reason to get a T-4 (Sounds are better)
Thing to think about is a used T-4 could be a problem if
not taken care of or gigged a lot of the time. Don has good
advice. Lloyd