no, the manix isn't much bigger at all. if it helps, the spyder hole and lanyard hole match up on both models. the mini has a 1/2" shorter blade with the belly and spine proportionally reduced to keep the same leaf shaped profile. the butt of the knife is abbreviated. like i said the lanyard hole is in the same place on both knives so it looks as if they just cut off the butt of the manix.
IMO go with the mini. the blade is marginally smaller, but still "big" compared to other knives. and the handle is better IMO because they shortened the butt end of the knife. it's smaller, more compact but still a MANIX!