As a fan and user of natural performance enhancing supplements, I am curious of anything that comes to market and would hope as science improves more natural products would come to market that have real results.
Dileucine while it I do believe the study done on it and for the "science" it seems great as not many natural products fair well. The study shows overall strength increase and increase in leg press.
That being said, as with all natural anabolic supplements, its minutia as these small strength increase, I doubt would make any difference. Do you believe adding 80lbs to your leg press would result into measurable/noticeable muscle gain. Maybe if you took it for year straight and never wavered on training you may see result.
Then you get down to price... you don't get much bang for the buck. If I were rich perhaps, I would take it as a staple supplement, but for the little it works, may not be worth me unscrewing lid on a bottle and swallowing.