The only thing I had noticed when on a while back was water retention. That being said. IT DOES WORK. As stated before, it is not the end all be all, but if one is looking for am edge, its a good safe way to go. Its funny as to the timing of the post because I just ordered SAN's Infusion and V12. I have some good friends that have competed in the past( AS users ) who are using these two currently and said good things about them.
As with any "SUPPS" I try to keep my expectations realistic. Your not taking AS. So any small benefit should be viewed as positive assuming your wallets not cleaned out. Later