To move away from tipping and keep the thread open, I'd like to look at the DDP decision. It seems to me that unless the OP has one or fewer other TS options that she is interested in paying OOP, she is better served by paying OOP for HDDR and DDPing the others. As she has stated that she is going to use the DDP credits, I suspect that she doesn't have any other opportunities that she feels she would be missing on.