The last half of the larger Club World cabin is really quite noisy - I found it so noisy it was hard to sleep on an overnight back from JFK recently. The difference in noise between row 2 in F in the nose (on the outbound) and row 20 in CW (on the inbound) was really very noticable.

I would always try for the upper deck - any seat, mainly due to less noise and it feels more private (given that the seating is only 2-2).

The larger CW cabin is not very private.