Absolutely, this to me if the pinnacle of off-the-shelf engineering design. To think, the guys who designed the falcon, and that includes the construction crew who worked on the actual props, managed to take a metal and timber shell and turned it from a fantasy into a craft that we could believe was real.
Since it made its first appearance in 1977, the Falcon has since obtained a series identity (YT-1300 series) a whole history - even a novel has been written "Millennium Falcon by James Luceno" in which we learn the history of Han and Chewie's ship. I'm not entirely sure as to who exactly was reponsible for the majority of its design, but its the work of a genius.
Curiously, the interior of the Falcon as seen (canon) in the Star Wars movies, does not fit into the exterior sets, which are smaller than their interior counterparts - and that includes the cockpit. Such is the difference in scale that Mayhew and Ford had to sit in a soundstage cockpit for the Falcon that was missing a floor so their feet could stick out.
Actually the guns were also another issue that I like to bring up. If you look at the standing prop for the Falcon in the hanger on Hoth (the empire strikes back) you will see in a couple of scenes while Solo is conducting repairs that the gun turret is supported above the gun port windows by a single upright ROD. I suspect somebody decided to cut corners and yet it ended up on film. You can see that ROD in this image: [link]