I have never had any of the previous versions, so I don't know, but the instructions are available on www.LEGO.com, so you could probably find out that way.
As soon as I can get my hands on a Y-Wing fighter, I should have all the necessary elements for some great Death Star Trench Run photos. Two TIE fighters to escort Darth Vader's TIE, two X-wings, a Y-wing, and the Millenium Falcon bringing up the rear. I suppose I also need to build a turbolaser tower or two to defend the trench, at least the one that GReased Porkins ;)
Thanks for looking, and for all the comments everybody!