We've stayed at the PP ('02) and the GC - concierge level, DCA view ('04 - points).
PP: Nice hotel if you get a nice view. We were celebrating our DD's 1st bd (March) and they upgraded us to a DCA view. It was spectacular. The walk to the parks is not too bad. We had booked the room for about $99. They were running a special on expedia.
GC: We stayed on points because we had extra points and our DS was only 3 months old and we didn't want to fly from CA to FL.
1) Thought the rooms would be bigger
2) Enjoyed the concierge lounge. We visited it many times during the day and evening (great cheese and wine!!). We would eat a big lunch at the parks and then snack at the lounge during the rest of the day.
3) Paid a lot of points (~108 for two nights). I called a couple weeks before our stay to confirm our reservation. The cast member told me the price of the room we had booked ($350 each night) and it was significantly lower than the point to $ ratio used on these boards. We are talking about $300+ difference.
4) Love the entrance to DCA --- very convenient!!!
The GC does run specials, however it is difficult to book a room. If you want to experience the hotel (very nice ambience and decorations), points may be the easiest way.
Regarding the parks... With the 50th anniversary, the parks are very busy. They are heavily advertising the parks in the So.Cal area. So, there will be a lot of locals there. I would say 2 hard days (commando style) and 1 casual day (revisit what you missed). DCA is usually less crowded than DL. However, we've seen 4+ hour waits for the rapid ride!!
Enjoy!
PS: the points for DLH are lower during the 50th celebration -- may be worth it!