Right now I would recommend DWA, mostly because one of Dallas Zoo's best exhibits, its reptile house is still closed and isn't reopening until the spring. with rare species like Perentie, Tuatara, Gray's Monitor, Dusky Gopher Frog, Ethiopian Mountain Adder and more, it's definitely worth a visit when reopened. Dallas also has one of the last Maguari Storks left in the AZA. DWA however is home to a lot more rarities, Southern Philippine Hornbill, Shoebill Stork, Antillean Manatee, Red Howler Monkey, Brown-Throated Three-Toed Sloth, Dracula Parrot, Black Tyrant Hawk-Eagle just to name a few. With the reptile house open I rank DWA and Dallas Zoo close and your decision would end up if you favor rare birds and fish more or rare reptiles more. But without the reptile house open, I would fully recommend DWA, and a return to Dallas Zoo in the future when the renovations are over!