As WDW vets, I think you will be pleasantly surprised by CS. I much prefer CS at DLR over WDW. Also, don't ignore the TS options at DLR just because you don't have reservations, if that is a concern of yours. ADRs are just not as critical at DLR as they are at WDW for most of the TS restaurants.
At DLR, my favorite CS is Hungry Bear for the tomato sandwich. My DH's favorite is the French Market for the French Dip, while I share the stew with my DD4. They often have a band playing at French Market, and it is such a great people watching location. My favorite part? Just pop right around the corner for dessert at the Mint Julep Bar for the amazing Mickey Beignets. SOOO good!!!
At DCA, all of us love Flo's. My two girls share with each of us. I always get the turkey meal and share with DD2, and DH lets DD4 pick, and she changes it up each time. I love the rolls! So tasty!
At DTD, we like the Mexican restaurant, the counter service one. The name is escaping me right now... sometimes, when in DCA, we hop over there for a quick meal and then head to DLR after. It takes such a short time compared to park hopping at WDW that it's easy to do. We also like EoS, but they have that at WDW.