Saving them for business class deals on flights. They just ran a deal for 50,000 points business class all over Europe. From what I’ve seen, flying is the best way all these CC points - best bang for buck compared to redeeming for cash or hotel points

The hotel collection with Platinum is a good deal too, guaranteed room upgrade if available and $200/year in statement credit and then an additional $100 for dining and spa, and services at a hotel booked through the hotel collection