We do find NPX 300 sounds a touch better than XPS on legacy equipment, both PSUs have DR, both big transformers. A dealer can dem.
NPX 300 also has soft start, 0.5W standby and inter-product communications for system integration e.g. lights and power control.
If I had 272 with XPS I would upgrade the 272 to 222 first. Then use the XPS DR on the 222. XPS is very good.