I "second" everything Big John said. I purchased some GGD Heavyweight Pullmans, then found a pair of 12-1 Pullman Brass Sleepers 3rd Rail, and I had already purchased their USPS Post Office car.
Ended up selling all my Lionel NYC and C& O George Washington Heavyweight Pullman cars .
So I am living proof that John is dead right when he wrote: "But be warned... once you own a set of GGD cars, you will feel the need to sell off your other cars to buy more GGD cars! They are the very best in 3 rail scale!"
The other warning though is you have to be running wide radius curves for these cars to look right and run well. My minimum diameter is 096, and many curves are wider.
