I have added a few Athearn Blue Box Kits to my roster and have to say that these kits are very nicely done and build into great freight cars! However, they are almost 1/2 the weight that the NMRA recommends them to be. So, adding weight is paramount to there good running, as String Lining can occur with these cars if they are at the front of the train! Of all the Athearn Blue Box Cars that I have, I have to say I like the tank cars best! I have several petroleum single and triple dome tanks cars and several Chemical Tank Cars, which are my favorite!