In the Northern Virginia area with a significant Vietnamese population, there are dozens of pho restaurants, many of which have been there for 15+ years, yet the differences from bowl to bowl are noticeable.
Eden Center, Seven Corners VA! If you are ever in LA, check out Westminster in Orange County, it is half Vietnamese. For some reason I preferred the pho in America to Vietnam. But banh mi I discovered in Vietnam and I think that might be my favorite sandwich. Fingers crossed that this pho restaurant in Chengdu happens.