heard that hemp seeds are a great source of protein, besides omega 3 .... better than flaxseed.
The comments you are referring to need to be put into context.
First, most of the information you are hearing is coming from the marketers of hemp seed. I know of no scientific body (or study) that is recommending hemp seed for anything.
Also, we don't need a "great" source of protein as the foods recommended here provide more than enough protein and remember more is not always better and often times it is "worse." I have posted data here recently on longevity studies showing that "lower" (but adequate) protein intake may be best.
In regard to omega 3's, we have to look at nutrients in regard to nutrient density, which is how much of the nutrient there is per calorie. Flax seed has the highest omega 3/calorie content of any seed or nut and has a much better omega 6/omega 3 profile than hemp seed.
If you have not read the threads in the hot topics on essential fats, fats, nuts, etc, I would highly recommend it to help put all this in persepctive of the bigger picture.