i know, a comparison article has already been written up in GR magazine this month, but somebody confiscated my copy before it even got to my house!!! but i dont want just one mans opinon on the matter…i want EVERYONES OPINION as to the real life operational habits of these two engines…i myself do not like the noise nor the gearing of the SD45, so i removed the motors/worm gears from mine and it now is a dummy unit…i do not own a SD40-2 but i have seen one run (outside, of course! ;^)) and tho it is substantially lighter than the SD45, it ran beautifully…the stobe light on the roof was/is a nice touch to if you ask me…but i have heard some bad things about the USAT 3 axel trucks…has something to do with the ‘added’ axel (the 3rd axel basically)??? something about the motor block being the same as the gp’s and f3’s,and the 3rd axel (pivoting if i remember correctly) being an ‘add-on’ and having problems…can anyone elate on this subject???