Finally got to Nava Thai last night. As soon as I walked in, I recognized the waitress and the chef from Dusit. I had the seafood in chili sauce; my friend had chicken lard na and pork kaprow. All were top-notch.
With Ruan Thai, Nava Thai, and Dusit Thai (highly under-rated on Chowhound) within a two block area, Wheaton is THE destination for excellent Thai dining.