I do believe that this is a Great Blue Heron. The other point I would suggest is that you not crop the legs off as you have done here. Maybe I am fussy, but I like to see the whole bird, unless you are just doing a head shot.
I believe your right....I think it is a Heron. How about this pic....I had the whole body in this one, the other one the feet wernt cropped they just were not in the pic.