I've had the veggie burger at a couple of places, The Liberty Inn in World Showcase (that one was rather dry and needed lots of toppings from the bar! Good with lots of pickles and ketchup though!) and Sci-Fi drive in. The Sci-Fi one was pretty good. Neither of them seemed like Boca Burgers, I eat those all the time. The last time I went was in February though, so it might have changed since then.
Sorry, no pictures! I didn't take pictures at Sci-fi because it was too dark and I felt weird!