I was on a 6 week H-Drol cycle and I got insane pumps and my strength went through the roof. Made some good gains, probably around 12lbs in the 6 weeks. Kept about half of it afterwards.
Although most people say they find it very mild with little/no sides, it hit me pretty bad. I was agitated the whole time and short of temper. The night sweats were pretty bad and my blood pressure shot through the roof. So much so, that I nearly passed out in the gym a few times towards the end of my cycle.
It's great stuff, but I wouldn't take it again, as the negatives outweighed the positives for me.