Is there a definite change from screw down spool retention and push button retention between these two models?
Yes, Clint --
The earlier 280 has a different spool shaft, drag knob, and the spool must have the drag nut unscrewed to remove the spool.
The later 285 -- which is the pre-cursor to the 330 Finessa -- has a push button spool release.
Best,
Fred