Many will say True flight is top of the quality heap, and they are very good, though I've used plenty of Gateway's with no complaints whatsoever. Some of the Gateways are a little higher profile than the True flights, and I can usually find a better deal on Gateway's but not always. I'm rather partial to Gateway's Trebarks, which look great with barred feathers IMO, but I like True flights barred better for appearance sake.
I've not used AMG yet but have heard nothing but positives about them, they don't have any barred patterns as far as I know.