The 52SE is a great speaker.
With that being said, the Contour S1.4 is much, MUCH better. I used to own the S1.4, and swapped A/B back to the 52SE in extensive auditions, same systems, when I was deciding.
What you will get with the S1.4 is much deeper and tighter bass with more output and a bigger, more dynamic sound overall with a larger stage. The cabinet is significant better in the S1.4, and the ability to mount the speakers right on the stands comes in handy too.
What I would suggest is trying to get a pair of S1.4 in house to try them out. If I was going to guess, and assuming you have the room to support them (no dyns like small rooms), then I think it will take about 10 seconds of listening to make your decision.