How many avios do you have/can you spend?

If you earn faster than you can spend, go CE, because why not? Otherwise the main advantage is the empty middle seat and/or some extra legroom.

I like legroom a *lot* so I'd probably do it even on a 100k balance unless it would jeopardise a big redemption. Even then I'd be likely to go for an exit row seat in preference as I'm not too bothered about the empty middle.

If I were six inches shorter, I'd be at the back of the bus given that you have lounge access anyway. (NB the CX lounge in CDG is excellent, not tried the AA one yet).