Many folks say that the FT's ARE scale size. They were a tiny bit shorter than the F units in real life.
I like my Burlington AA set, but it was expensive powering the dummy A unit. I had to buy another powered FT to get the power train. Then the E-units were two different designs that could not be made to synch, so I bought a pair of Dallee units.
They have the same drive train as all the other diesels with the "China drive" so they are powerful, quiet and smooth. Do I recall that they do not have flywheels, though? Can't remember. Anyway, they run great, like almost all of the diesels built in the last eight years or so.
I too, would like some B units for this loco, and now I know why I never see any for sale. .