RE: What's the difference? Four-Star or Somethin' Extra
For the beginner, the Four-Star is capable of a bit less demanding flight, although some would argue the SE is quite easy to fly, too, when set up for it.
For the experienced aerobatic flyer, the SE is capable of a bit faster rolls and tighter loops, if that's what is desired.
For someone with an eye on pattern competition, the Four-Star might provide smoother pattern maneuvers. For the 3-D aspirant, the SE might come closer to performing in that fashion.
However, you've asked about two fine examples of planes, both fairly easy to build and sturdy. Pleasing to the eye, too.
What did you have in mind?
Good luck,
Dave Olson