both have pro's and con's PA28 I find is more stable to fly and better for stalling.
But the pa38 is just a great plane to fly. I can't choose a favourite!
Both reasons making the PA38 by far the better training aeroplane, as almost certainly "better" in your parlance means "less frightening".
The PA28 is a good tourer, but I wouldn't go back after discovering the joys of the AA5 (100+ hours in each, so have had a chance to make a reasonable comparison).
G