Depends on which one your talking about. The Thick Blank/Printed ones like
these as nice and thick but have a kind of rough texture to them and are blank or lasered where IMSO is dyesub. The dyesub set is only 1.00mm thick and IIRC IMSTO uses Vortex or BSP for his caps which are ~1.5mm/1.3mm thick, so your IMSTO set should be thicker if I'm right. Also they are OEM profile where IMSTO is cherry.
Otaku = blank, I don't think they are the same as the ones on Geekkeys.