They are more or less the same, although there have been some small changes over the years, I think many of which happened before it became the PT series anyways. New small round headlights, hinged/tilt rear hood, small changes to the quick attach, etc. I think functionally they are more or less the same.
At some point they are supposed to release a Terex PT-30 with a 101 inch lift height instead of the old 80 inch height. The arms have been beefed up and revised. I have not actually been able to get an answer from anyone on when this would actually be available however. Originally was told June, but havn't seen anything yet....