The pumps were bullshit as far as Im concerned. But I did get denser and broke over 20 personal bests in one month on the stuff. The No2 by MRI, since it has the time release. Gave me awesome strength increases. I was stuck at 315 fro 4 reps for a year, within a month I was up to 7 reps with 315 on flat bench and 315x6 on Incline, not to mention 275x15 on flat, up from 12.
Also my deadlift went from 465 to 510 in the same month. Great stuff. I posted a thread on it a while back. Im still on it, even though my training is suffering from this back injury.