The 2 watches are "2 sides of the same coin," if you will. I love both, but the Squadra is NOT a water watch. It can take the accidental plunge, but it's not designed for "prolonged water use."
That said, the Reverso Squadra World Chrono is an amazing movement, since you have the world timer coming through the back. If you don't think you'd use the world time function as much, I must tell you that the Polo Fields version is VERY interesting due to the back having the names printed on a sapphire disc so that you can see the rotor sandwiched between the 2 dials.
If it's an either/or, I'd stick with the EWC. If it's an addition to your JLC stables, I think it's a great addition. The titanium is 1500 pieces, the Polo Fields is very low production.
Just my thoughts.
-Dean