Yes, the sandwiches are as good as everyone says they are! We were staying off the strip this trip, but at my mom's insistence, made a special visit to Planet Hollywood just to get Earl of Sandwich. The Caribbean Jerk Chicken is great - slightly spicy and tangy, but my favorite is still the seasonal holiday which is like Thanksgiving in a sandwich.
Yes there will be a line, possibly quite long, but don't be discouraged. It will move quickly and soon you will have your grubby fingers all over a delicious toasty sandwich. FYI there's a location opening up in Downtown Disney too, so now LA/OC-ers can get their sandwich fix without going all the way to Vegas.