I'll make this pretty simple. It's good stuff!
I used to be a big BCAA consumer, I had many bottles of xtend kicking around. When I stopped taking them my body fat went down, my wallet got thicker, and my stomach got less upset. Strength didn't change. I haven't looked back, until Millennium came out with RPG. I told them I'd try it although I'm (understandably) suspect of BCAA's since my experience has been that they're worthless.
Millennium hasn't let me down yet, so I figured what the heck, I'll give RPG a try. I have not ever taken it by itself, I've always taken it mixed with Ragnarok. Since I take Ragnarok and have been taking it for the past I don't know how long -years though- I feel that any change was attributed to the addition of RPG.
The bottom line is that my training weight have gone up a noticeable amount. A couple weeks ago I pressed 405 + 90lbs of chain, a 20lb record for me that has stood unbroken for well over a year. I pulled 545 standing on a plate, which was another PR for me. There have been others too. These are tough lifts for me, and they don't go up for no reason, I'm way past the easy gains stage.
These supplements are all a gentle push in the direction of progress. IMO they greatly depend on proper diet, sleep, training, and heart to function right; in other words, you can't make up for lack in training with good supplementation, although I do think you can mitigate damage from non-ideal circumstances.
So what did I notice? I'm lifting more than I ever have before. It's that simple. My diet has been very consistent except for the addition of RPG, and over the past several weeks, I'm a couple pounds heavier (I do not think I'm any fatter FWIW). Like I said before, I mix it with Rag pre-workout and sip it through my workout. I can attribute my strength increase to slighly refined training methodologies and RPG. Everything else has been the same. The training is hugely important, but it wouldn't have helped me gain the weight -I have a very good pulse on my overall volume.
I will continue to use RPG, although when I decide to drop a weight class I may only use it on my most important days.
I'm pleased with the results, although now I have 1 more thing to add to my supplement list, lol.
One more thing worth mentioning, and I've said this before, but guys, buy supplements from companies that you can trust. Look at the ingredients on RPG, it's all good stuff. There is so much crap out there, and I'm not even mentioning what brand or what company, but a shocking amount of stuff out there is not only not good for you, but outright bad. Your health is important, don't blow it and your money on sub par ineffective supplements.