I had one yesterday and one today. I agree that the meat is slightly sweet, but the homemade mayo is what seems to give the sandwich a really sweet taste. Luckily, once you bite into a couple of the peppers, the sandwich tastes less sweet. I guess I'll have to trek out to the Dot to try the "beef" version at Banh Mi Ba Le.
In the past, I have noticed both GG and Michael say that the sandwich artist cut the vegetables individually for their sandwiches. The carrots, onions, etc. were already cut when I got my sandwich these two times. The only thing she cut was the cilantro with her scissors.
The bread is very tasty too, nice and crunchy after she puts it in the toaster oven.