I went with the C-80. I am very happy with it and feel it is more than adequate for the 2520XL. It will also allow you to have more "real estate" to flush mount other electronics now or in the future. It's just my opinion but I did not want to add anything to stand in the way of the front windows as the view is already somewhat obstructed by the pilot house structure. Also, as I will describe in another post, I have moved the boat to South Florida and the full view (and breeze) out of both open front windows is just fantastic.