ZBrushCentral

Importing and exporting around Zbrush

Hi,

I see there are only a few formats to export tools out of Zbrush.
Whats the difference between stl. and Obj. , and whats the best? (I know stl is for 3Dprinting but how does it compare to obj information wise).

Once I use these formats to sent to Rhino or Sketchup to work on them, which one is best to use to send back to Zbrush.

Is there a way to get more file options because not have 3ds or even Skp is very limiting.

Regards,

Simon