I've heard so many horror stories about their customer service and all the ones that I've seen have some fatal (to me) design flaw like bungies or just being way oversized, so I've avoided them. Since there are so many excellent choices in wings these days, why bother.
OMS seems to have had distribution in recreational dives before any of the smaller tech oriented companies, so that's what a lot of divers bought, probably influenced by their teachers who were using shop brands. With halcyon, DSS, oxycheq, and dive rite easily available online, there's no shortage of really good wings.