i have way to many spyderco's to lis.t Ask sal and I carry mine 5 out of seven days at least.Some of best money I've spent on a round hole in a long time.
they might be on the right side so it doesn't rub the liner or handle when you open it. other wise when you thumb the blade feel or hear or a scraping sound.
you will for sure see a rapid desend into tia pia made knives not just bitchmade and spyderco, kershaw, sog ect... are already bidding against each other.
It probally has to due with fact they are focusing on other orgins of production knives "cheaper" made/japan/tiawan/china.
Not so much the high/end tactial models.
It is rattling because the perrin's sheath is injected molded. And the moran is for fitted differently (better).
Mike Sastre with River city sheaths Made my perrin sheath and lum tanto both in the waist carry or on my belt.