Like a lot of this stuff it is pretty much tastless, much the same as lean meat is tasteless. So it's all down to the sauce.
IIRC the amino acid thing was an early "scare story" against the vegan diet. They then said it was ok if you got all the amino acids from different foods and then said it dont matter at all as long as you had some protein! As well as Soya I was led to believe sesame seed also had all the amino acids together.
I'm sure cuttting down Brazilian raid forests is not good, but crops are a far more efficient method of producing food. Eat meat by all means, but dont pretend you are saving the planet .