What is the difference between (a) a series of semiquavers with a semiquaver rest in between every pair, and (b) a series of staccato quavers where sound/effect is concerned?
The staccato sign means make the note about half as long as it originally was. The 'about' is the criterion here. It's down to the discretion of the player as to how long 'about' is.
Writing semis, with semi rests between is far more accurate for timing - each rest is the same length as each note. i've often pondered on this one, and think it comes down to the composer allowing/not allowing some leeway for future readers/players.
Should a composer want to be more precise, there's always the options of mezzo-staccato or staccatissimo as alternatives to dots and rests - but the latter will always be more accurate.
Staccato quavers aren't necessarily the length of semiquavers (they could be in more of a 40:60 ratio with the rests right afterward, for instance). Semiquavers with semiquaver rests in between are strictly in a 50:50 ratio in comparison. Staccato quavers are flexible length-wise; semiquavers are not.