I have redeemed avios on BA from NCL 3 times in the past year (LHR, DXB and HKG). If you can spend £10k on an Amex card in a 12 month period, get a BA Premium Plus card and get a free companion ticket.
For me, BA is far better than KL who give pathetic miles for short haul economy flights (even with a 100% bonus as a platinum).