Well everyone has said it all lol, but still want to give my 2 cents!
Before RFC opened in DLR, I had only eaten in them twice: Once in Las Vegas and second time in Singapore and it felt soooo cool at the time! I had never done many of those theme restaurants and this really worked. I tried to go when I went WDW when I saw they had one at DAK (perfect theme lol) but was too busy and didnt want to wait.
So when I heard one was coming to DLR my old stomping ground, I was really, really excited. As someone said it IS the theming thats the most fun and feels the most 'Disney' out of all the DTD restaurants. So it is great to get you in the mood and it is fun.
Buuuut, now, sadly I dont really like going as much. I probably been to the one in DLR about a dozen times now since opening and yes the food IS overpriced and its not that great (although yes the burgers are actually quite good). And the crazy wait for it is too much at times...which clearly speaks to its popularity though. But there are better restaurants in the area and although the price points are all the same, the food is better!
But yes if you never did it, have kids, definitely go! I been on other websites where RFC comes up and people are pretty brutal lol. I'm surprise people are more positive here about it. But no, its no longer the restaurant I MUST do when I go to DTD anymore...but generally if someone wants to go I will do it.
But yes, that place is ALWAYS so freakin busy lol. I chalk it up to not just its theme, but its location being so close to the theater, parking,
Disneyland Hotel and monorail, this and ESPN zone seems to have the 'sweet spot' in terms of foot traffic and everyone constantly passing through this area going to see a movie, coming and going to the hotel, getting off the monorail, etc. Add to the fun design of the building and you got a hit!