JL is not usable on a oneworld award until April next year ... so your question is a bit academic (unless you really think you need 5 months to make up your mind before redeeming the award).

JL is quite poor in J compared to CX. Closer to AA than to CX for J service. NRT lounges are primitive (hint: the AC at NRT is generally considered to be superior to the JL J lounge). Nothing like the Wing/Pier is offered by JL. Overall JL is an average to poor airline, but has a couple of specific premium routes that have stellar service. If you happen to fly one of those routes (maybe 1% of JL services), then it can be really good (particularly in F), but otherwise it is dismal. JL brings new routes and cities to the table, but not an improvement in service over CX.