Tap vs Local Variables

tapper.rb

def level_descriptions=(input)
  write_attribute(:levels_description, input).tap do |_result|
    flush_cache :levels_description
  end
end

# same number of lines, one less method call, one less block, but pretty much the same as
# far as I'm concerned.
def level_descriptions=(input)
  result = write_attribute(:levels_description, input)
  flush_cache :levels_description
  result
end

# effectively the same behavior barring exceptions, has no variables
# probably harder for folks to read/understand, I would prefer either the two above
def level_descriptions=(input)
  write_attribute(:levels_description, input) ensure flush_cache :levels_description
end

# bottom line, I see no compelling reason to choose tap over a local variable or vice-versa.