Well if ya got the loot then they all could be fun and maybe worth buying. I have met some folks who didn't take to a "Rev" type sailed kite but liked a Spirit or Deca better. At one time I was a huge Deca fan especially the zero wind ones...but they are all gone and my Rev collection is still here.
However there is a reason why the Rev type sailed quads....Revs, Djinn, OSK, Riffclown, etc. will always be the benchmark....they just endure and work.
bt