For me and my family, it was one of the best time to do rides. We were at the DLR from 3/15-3/20 (defiantly a very busy time at the parks). After the fireworks on Wednesday night, me and my GF we were able to hit Matterhorn, TeaCups, Pirates and Haunted in about an hour.
Though this may not sound like a lot to some...we defiantly took our time strolling around the park and just enjoying the magic DL had to offer.
The next night we came back and did Buzz, Matterhorn and Indiana Jones in about the same amount of time.
If I can offer a tip....I would watch the fireworks right around the Tomorrowland entrance. Especially if you want to get a short line on Space Mountain, it's an easy walk, and you'll beat the majority of the crowd!