How much of a difference does protein make?

...i know protein is essential, but how many of you have noticed a dramatic difference in lean muscle mass by upping protein intake a considerable amount?...say you were taking in 200g/day and started going with 300+/day, how much difference did it make...some people swear by almost 2 x bodyweight and others say less is fine...

I noticed a big difference going from .5 g to 1.5 g per lb. Starting putting on some good size. This was inbetween cycles and the only thing I changed. I ate 1.0 g per lb while on and then cut back to .5 during clomid and a couple of weeks after jumped it up to 1.5 and put on a couple solid lbs. around 2 I think

i've noticed a big difference. . .