After this little tweak, I really noticed the difference in general build precision between cast and CNC aluminum trucks. All of my casts reduced, but never lost bushing squeaks just like in my little video. The bushing seats will bind the bushing even slightly no matter what. My Surf-Rodz RKPs on the other hand became completely silent.
Is this something worth spending $50-250 more for the average consumer? Probably not, but its an interesting observation regardless. Another reason I decided to write a bit about this was the never-ending debate by average consumers (non-competitive racers, since they were pretty much the reason for precision industry) and the difference between the two types not being worth the money.