I would take the LX-option in a heartbeat. You could still access the Polaris lounge at LAX, if you really wanted to (it's a bit of a walk from the TBIT gates for LX), but the *A lounge there is fine, too, and has an outdoor terrace.

The WK-hardware is essentially the same as LX (with different colours) and the soft product will be LX anyway, as it is a wetlease. And ZRH is a great airport for connections.