Had both - Several times
The Newage is an advance in evolution and is mechanically the better and stronger car.
But although the interior is newer, I never felt the build quality was much better in a newage. They are still a field of cheap plastic, switch gear and materials, and little or no refinement no matter which age. Once you get past the dated interior of a classic, which makes its a classic if you know what I mean, then apart from a door that has a slight more thud/ting as you shut it, I wouldn't say it much more of a nicer place to be. Its still very much a subaru.
The power delivery of a remapped Hawk is lovely. But then so is a remapped classic running a TD04.
Horses for courses - but pound for pound newages represent better value for money right now. Good classics seem to be fetching good money still, and the cheap shed clasics are cheap for a reason.