I have used both. I find them both to be good quality feathers.
If you are getting them pre-cut, AMG's are a little higher profile.
As others have said, the AMG's colors are brighter, and the quill definitely thicker.
They were less expensive last I bought them, but now I find them often as expensive as, and sometimes more than, the TruFlight's.
Made in the US also comes into play for me. These days I pretty much stick with the TruFlight's, preferring the thinner quills, along with the other factors.