Windham Weaponry assembly quality is better than the old Bushmaster. The Windham Weaponry barrel assembly jigs and barrel wrenches are very good.
Sadly, they still use motor oil on the barrel nut for barrel installation and they don't use any lube for buffer tube or castle nut installation.
They still use commercial carbine receiver extensions and they still don't stake the end plate.
Their gas keys are staked very well now, old Bushmaster was known for having "meh" gas key staking.
Their rifle length A2 handguards still seem to be very good like the old Bushmaster but their A2 stock kits are lacking in quality compared to the old Bushmaster... Specifically, their use of cheap commercial rifle buffer tubes, plastic trap doors and stock screw quality is lacking, old Bushmaster was basically using Mil-Spec A2 stock kits.