Based on my own experiences, If you are dieting or in calorie deficit mode for some time, or you are in low carb ( less than 50-60 g per day ) or you are doing intermittent fasting ( or you are not eating meals for a long stretch of time ), BCAA can preserve your muscle.
Otherwise, you don't need them.
There's truth to this post. They're the only aminos that are actually metabolized INSIDE the muscle. They posess an anti-catabolic property that is unique to only branched chain aminos, but nothing extremely magical.
A fair reference point would be that they are supposed to work slightly better than your average batch of kigtropins
