The Super Star Destroyer, with 3152 pieces, is nearly 50 inches (124.5 cm) long and weighs nearly 8 pounds (3.5kg):

While the Ultimate Collectors Edition Millennium Falcon had over 5000 pieces, and was 33" long, 22" wide and 8" tall! (84cm long x 56cm wide x 21cm tall), and was officially advertised as the biggest set ever made - it was almost exactly to Mini Figure scale as well.