Teresa:
Three weeks is a long time to be at Disney in a Value Resort, in my opinion. Most folks choose to stay at a Value hotel because they won't be spending much time in their room or at the resort. It is difficult for me to believe that you will be at Disney for that length of time and not spending a day or two or even more simply enjoying the resort. Although I prefer
Pop Century over the other Value Resorts, its food court may quickly become stale as well as its pool.
For a long stay, I would recommend changing things up a bit. Consider starting your vacation out at Pop Century to save money but after 5 to 7 days, and with the help of Disney, you can have your luggage transferred to
Coronado Springs Resort. The landscape, pool, and restaurants available at that resort will be a welcomed upgrade and make for a much more pleasant stay. You may want to even consider resort-hopping to another moderate resort like
Port Orleans: Riverside for the last week of your stay, again, simply to change your scenery, your dining options and the resort activities.
Wishing y'all a magical vacation!
Whitney