It's only okay. It's a great experience to have because they are so well known but the sandwich itself is just okay. Fortunately, we did not wait AS long in line (probably due to the weather) but I have seen previous lines that are absolutely not worth it.
The menu situation is very confusing because you don't get one. You need to look at the board behind the counter or the board at the very back of the restaurant. They are also cash only.