Dynatrac is a great company and builds quality parts, have their 35 spline kit with free spin hub on my superduty. However the G2 housing is US made, I have no idea where teraflex has theirs made, but Currie usually makes a quality product, no idea where it is made. My point in it being a wash is that they all cost about the same unless you are upgrading from a d30 to the 44 then the G2 housing coming loaded with shafts and locker can be a big savings.
Im not suggesting anyone go with anything here just did tons of research before making my decision and learned quite a bit about the options with each brand. I dont think there is one that will be drastically different in performance than the others but only time will tell.