Considering that the DDP is only $10 more per day than the QSDP, it is worth switching to the DDP even if you do only a few TS meals. Also, most CS places will let you use a TS credit for a CS meal if you don't want to do a TS for every night of your trip.
I think the QSDP allows you to have 2 snacks per day, but who needs more snacks when you already get a dessert with lunch and dinner?
JMHO...