I have had good luck with Mato V2, which is the brass equivalent with bushings instead of bearings. Out of about 10 GB only one had slop that became an issue latter on. In my case I had the gears binding onto the shafts because the tolerances were too tight.

Also as Ex pat pointed out in another thread, the bearings in place on some of those shafts are not doing anything as the gears spin freely on the shafts, I'll stick with the V2 boxes after reading this,