Not to poop on your review and/or your experiences, but I think the more "solid" feel of the white switches may be more due to the keycaps being PBT, than the actual switches being more solid... unless you accounted for that, of course, when you say they feel more solid.
Because that was my immediate impression when I switched from my ABS caps, to PBT caps on my Filco with MX Browns. The whole keyboard immediately felt different, and "more solid", but I know it's cause of my keycaps.