Sandbar - this is a great subject. I moved it into its own thread so it can get the attention it deserves.
My opinion is they like mid level salinity best. That would be defined as that which is found in the sounds and the lower part of creeks. One of the best speck grounds around Topsail are the creeks that feed into the New River - they are tidal though - they go up and down with the tide so they get an influx of salt each tide cycle but it is then diluted with the freshwater that comes from shore.
With that said, another of my most productive areas is very near an inlet and does best at high tide which is the tide cycle with the higher salinity levels at that particular point. So based on my limited experiences, it seems their range of salinity is very broad but in the 70-80% middle of the range (meaning all salinities but the lowest and highest 10-15% of the range).
As to the quality of the season, last fall was the best I have seen in many, many years but I expect even better this fall as we had such a mild winter again and the bait is so thick this year. It has certainly started strong.