If you are buying the dc tickets without the AP or other discount that may not include another park, you get to pick one of the other Busch parks for an unlimited entry for up to 14 days from first use. If you pay an additional $50, you can pick 2 other parks, Aquadica or Busch Gardens Tampa. We used our DC tickets at BGT (the park we picked as our other Busch park) before our day at DC, and they just scanned our DC tickets ( I had printed our tickets from the electronic tickets we were emailed after our online purchase). We went back to BGT after our DC visit, and we used our DC lanyards to get in.
We loved DC. The kids have still fantasized this will be an annual visit. I really enjoyed the relaxing day, the free alcoholic slushies from the one snack shack, and the slow pace of everything. We did not have to wait for food for very long, and there was plenty of seating. Everyone was kind, and the DC staff were very attentive to my inquisitive DD. She wants to be a marine biologist now.
We also went to Sea World, and the kids liked that too. It is also not as frantic as other parks we had been too. The crowds can be large though. We went the Sat. of Labor Day week-end, and the were long waits for food, and having to get into the Stadium at least 1 hour before start to get a decent choice of seat. We loved seeing the fireworks too. Shumu Rocks was fun, and we really laughed at the Seamore shows, the regular and the spoofing one. Pet show was fun too. We saw Allure and liked it, but I think the ice show is now there.
Have fun, DC and SW are great parks.