Originally Posted by xenole

£499 each one-way seems steep to me.

I would personally just stay in WT+ where you will get 8646 Avios / Miles return per person, put them into a Household Account and with another couple of thousand or so, you could use them next time for a cheaper one-way WT+ to CW upgrade (10k Avios each one-way)

Keep the nearly £1k (if you can upgade both ways) and spend it elsewhere - would even cover a couple of WT flights from LHR-JFK in the future.

As for comments about it being better upgrading on the return leg, personally I don't sleep on planes heading east and £499 for 3-4 hours sleep isn't worth it to me. That's 3-4 nights in a hotel where I can sleep properly for 8 hours+ should I choose!

There's always the slim chance of getting upgraded at the gate anyway.