YES, transports make a HUGE difference. They all have different sounds and will impact the sound more than you ever thought possible. They are a major factor and I have tested this personally using my DVD out then the transport, then comparing transports. Truely night and day, even to the layperson who is not into audio can tell the difference (I tried this on a non audio friend).
I played the transport game a while back and found that they made a very big difference...CEC very liquid and analog sounding, somewhat limited in dynamics but the best midrange this side of vinyl....vecteur...more balanced and almost the perfect compromise. Bottom line, listen for yourself to decide which transport but trust me it is every bit worth the investment!