It affects different people in different ways. I thought it was unbelievable stuff. After 7-10 days i could lift on average atleast 25% more weight on every exercise no problem. The week after it was even more. The lad i used to go with was gutted as it didnt affect him that much at all. The main thing for me tho was normally when you finish a set your not looking forward to the next one, on creatine however i was hurrying my mate up so i could get back on the machine! I also had a strange feeling that i could lift any weight in front of me.
The down side is when you finish a course you feel like a girl cos all the extra weight comes off the bar and you cant be arsed anymore.
Ive never taken steroids but for me this is probably the next best thing.